Régulation et environnement : Publications

We explore empirically the impact of the market sharing collusive practices that were implemented in the French public transportation industry between 1994 and 1999. We build a structural model of bidding markets where innovating firms compete for the market and have the ability to spread the benefits of their innovation through all markets on which they are active. Each local competitive environment shapes the distribution of the prices (the bids) paid by public authorities to transport operators. We recover empirically the distribution of prices and innovation shocks and we show that collusive practices had overall a limited impact on prices. Firms were in reality more interested in avoiding significant financial risks inherent to the activity, as well as the high cost of preparing a tender proposal. As a by-product, we perform a counterfactual analysis that allows us to simulate how an increase in firms’ innovation reduces prices significantly.

Emission trading systems are cornerstone policies to reduce carbon emissions. Although economic intuition suggests that broader allowance trading should be welfare improving, this paper proves that view can be wrong. Under an increasingly popular type of emissions trading scheme — tradable performance standards (TPS), multiple narrow markets can decrease emissions relative to a single unified market, so that restricting trade does not always harm welfare. We show analytically that, when intensity benchmarks are heterogeneous within a sector, this result can hold even if the well-known “implicit output subsidy” does not impact total output. Finally, we provide evidence that this concern can be of high practical relevance. Using a general equilibrium model of China’s TPS for 2020–2030, we show that broader trading results in significantly higher emissions (up to 10%), and decreases welfare relative to narrower markets when the social cost of carbon exceeds $91/tCO.

This paper examines an endogenous growth model that allows us to consider the dynamics and sustainability of debt, pollution, and growth. Debt evolves according to the financing adaptation and mitigation efforts and to the damages caused by pollution. Three types of features are important for our analysis: the technology through the negative effect of pollution on TFP; the fiscal policy; the initial level of pollution and debt with respect to capital. Indeed, if the initial level of pollution is too high, the economy is relegated to an endogenous tipping zone where pollution perpetually increases relatively to capital. If the effect of pollution on TFP is too strong, the economy cannot converge to a stable and sustainable long-run balanced growth path. If the income tax rates are high enough, we can converge to a stable balanced growth path with low pollution and high debt relative to capital. This sustainable equilibrium can even be characterized by higher growth and welfare. This last result underlines the role that tax policy can play in reconciling debt and environmental sustainability.

Firms receiving independent signals on a common‐value risky project compete to be the first to invest. When firms are symmetric and competition is winner‐take‐all, rents are fully dissipated in equilibrium and the extent to which signals are publicly disclosed is irrelevant for welfare. When disclosure of signals is asymmetric, welfare is highest when firms are most asymmetric, and policies that uniformly promote disclosure may backfire, especially when competition is severe. When firms strategically select their disclosure policies, a moderate subsidy for disclosure induces a low correlation between firms’ policies, and thus maximizes welfare.

We study a sequential experimentation model with endogenous feedback. Agents choose between a safe and risky action, the latter generating stochastic rewards. When making this choice, each agent is selfishly motivated (myopic). However, agents can disclose their experiences to a public record, and when doing so are pro-socially motivated (forward-looking). When prior uncertainty is large, disclosure is both polarized (only extreme signals are disclosed) and positively biased (no feedback is bad news). When prior uncertainty is small, a novel form of unraveling occurs and disclosure is complete. Subsidizing disclosure costs can perversely lead to less disclosure but more experimentation.

Between 2005 and 2021, France has generated more electricity from fossil-free resources (491 TWh/year on average) than its gross domestic consumption (481 TWh/year). Therefore, in terms of total surplus, the French electricity sector should have been barely hit, if at all, by the surge in fossil fuel prices during the 2022 energy crisis. In practice, however, the French government spent billions of euros in subsidies to electricity consumers, the incumbent utility – who operates the whole nuclear fleet – recorded its worst yearly financial result to date, and total electricity imports exceeded exports for the first time in more than 40 years. Although these outcomes can largely be attributed to bad luck, the extent to which they could have been mitigated through better market design and public policies is an open question. This article argues that existing policies, through their implied incentives to share and manage long-term risks, played a critical role in how France navigated the energy crisis. Consistently, reforming long-term risk-sharing mechanisms has emerged as the most pressing issue to address. Looking forward, however, updating short-term wholesale market design so as to better support a low-cost and reliable energy transition will likely prove increasingly important.

How do environmental information and awareness interact to improve environmental quality by changing consumer behavior and firm strategies? This article provides theoretical insights using an original differentiation model within a general framework whose specific cases have been studied previously. On the demand side, only informed consumers differentiate brown from green product quality, while uninformed consumers consider these perfect substitutes. Moreover, all informed consumers value the green product and devalue the brown product as a result of an aversion effect but are heterogeneous in their environmental awareness. On the supply side, two firms offer different environmental qualities and compete on price. We consider two types of environmental campaigns: one that increases the number of informed consumers and one that increases the environmental awareness of informed consumers. We show that these campaigns crucially determine three market configurations: segmented; fragmented, with a brown product that appeals to both uninformed consumers and a fraction of informed consumers; and covered. Assuming that the greenest consumer behavior is abstention, we find that both campaigns do not always lead to better environmental quality; that is, a situation in which all consumers are informed and some highly environmentally aware is not necessarily the greenest situation. Depending on the aversion effect, the budget of the campaign organizer, and their relative cost-effectiveness, information and awareness-raising campaigns must be carefully combined to achieve the best possible environmental quality.

The Clean Development Mechanism is one of three flexible mechanisms included in the Kyoto Protocol. It enables Annex I countries to finance emission reductions in developing (non-Annex I) countries and use the credits thus obtained to meet their quantified emission reduction commitments under the Kyoto Protocol. The CDM had two objectives: to reduce the costs of compliance of the Annex I countries’ emission reduction commitments, and to assist developing countries in achieving sustainable development and in contributing to the ultimate objective of the UNFCCC. The major part of certified emission reductions (CERs) comes from renewable energy investments, reduction of non-CO2 greenhouse gases (HFCs, PFCs and N2O), and energy efficiency projects. The geographical distribution of projects and emission reductions is concentrated in a few countries: China, India, Brazil, and Mexico. A substantial amount of CERs was created under the CDM, but the uneven geographical distribution of projects and the lack of consistent control of projects’ contribution to sustainable development have been arguments to contend that the CDM did not fulfil its initial objectives. The restriction by the EU in 2013 to use CERs in the EU-ETS brought down prices and the market for CERs has not recovered since. The CDM was discontinued as of 30 June 2022 and requests for exemptions were considered on a case-specific basis. Nevertheless, the CDM has continued to function while parties are waiting for the flexible mechanisms created in the Paris Agreement of 2015 to become operational, in particular the Sustainable Development Mechanism of Article 6.4 which is similar to the CDM in its objectives.

We study a model of non-cooperative interaction between two infrastructure managers (IMs) for international rail transport. We compare equilibrium access charges when the IMs are unregulated and regulated. We show that cooperation among IMs eliminates double-marginalization to the benefit of passengers and IMs. We also show that the delegation of access charge collection with adequate transfers allows the two IMs to reach efficiency, both in the unregulated and regulated régimes. We study the effect of differences in regulatory policies, and analyze the effect of monopoly power of train operators and competition among high speed and low speed train routes on access charges.

The article estimates flood risk perceptions by exploiting the different release dates of flood risk information around Paris from 2003 to 2012. This period is characterised by the absence of significant floods since 1955, making flood risk less salient. We apply a stacked event study to detailed property transaction data combined with geo-localised amenities. The results show that transaction prices for similar properties are 3-7% lower following the release of information if they are located in a flood risk zone, and that the effect persists, at least over the period we analyse. The results are robust to varying the control group to a neighbourhood at different distances from the flood risk boundary. The effect is more negative for flats on the ground floor. We find no evidence of sorting among buyers along different characteristics, in particular based on past exposure to flooding in their previous municipality. The results indicate a significant effect of flood risk information in a context where we can isolate it from the financial consequences of insurance cover and from flood damage per se.

There is a lot of expectation surrounding energy sufficiency as part of the energy transition. It may result from an increase in energy prices, but it could also be a conscious choice. In this case, it would be the consequence of an adjustment in preferences or a reduction in behavioural biases. Changes in preferences can be modelled as an adjustment to the relative weights attributed by individuals to durable goods, energy or even non‑durable goods. Here, we show that the macroeconomic impacts differ largely based on the type of adjustment, which we can use to guide public policy decisions. This then leads to the question of how to bring these preference adjustments in practice. In addition to nudges to reduce behavioural biases, preference changes can stem from a collective organisation and better information, in particular regarding the co‑benefits of energy sufficiency.

We assess optimal deterministic nonlinear income taxation in a Mirrlees economy with a continuum of risk‐averse agents whose utilities are quasilinear in labor. A weak redistribution motive makes random taxes more likely socially dominated by the deterministic policy where after‐tax income lotteries are replaced with their certainty equivalents.

We investigate the impact of different public transport pricing schemes on daily commuting habits. Psychological inertia, car stickiness, complexity aversion, or skewed perception of prices are expected to influence decisions. We build a controlled experiment, where participants make transport decisions and face various public transport tariffs. Our findings indicate that players are rational as they reach the Nash predictions of our model, but cognitive biases inherent to users are also present. Peak/offpeak and two-part tariffs prove to be more successful in encouraging public transit use than flat fare subscriptions, possibly due to a preference for flexibility and the ability to take past experiences into account (congestion and incident) in future travel choices. Thus, this paper suggests that well designed pricing strategies are useful tools to promote public transit use and reduce road congestion.

We study a sequential experimentation model with endogenous feedback. Agents choose between a safe and risky action, the latter generating stochastic rewards. When making this choice, each agent is selfishly motivated (myopic). However, agents can disclose their experiences to a public record, and when doing so are pro-socially motivated (forward-looking). Disclosure is both polarized (only extreme signals are disclosed) and positively biased (no feedback is bad news). The extent of disclosure is non-monotone in prior uncertainty. Subsidizing disclosure costs can paradoxically lead to less disclosure, but more experimentation.

A present-biased decision maker (DM) faces a two-armed bandit problem whose risky arm generates random payoffs at exponentially distributed times. The DM learns about payoff arrivals through informative feedback. At the unique stationary Markov perfect equilibrium of the multi-self game, positive feedback supports greater equilibrium welfare than both negative and transparent feedback. Regardless of the form of feedback, the DM’s behavior exhibits indecision, deriving from their desire to procrastinate. We relate our findings to the theory of self-prospection -the process of imagining future goals and outcomes when seeking motivation in the present.

This paper studies the question of how to target aid after a natural disaster. Disaster aid programs often use property damage as a criterion for eligibility. A household’s ability to insure against shocks may be harder to observe but more important in determining how the disaster affects welfare. We develop a model of household demand for reconstruction aid and estimate the model parameters using a household survey following the 2015 Nepal earthquake. Key model predictions are validated using a spatial regression discontinuity design. We use the model to estimate welfare from counterfactual targeting strategies. Conditioning aid on property damages does not significantly improve welfare relative to allocating aid randomly. An untargeted approach that divides the aid budget equally among all households in the affected areas yields larger welfare gains. Using resources to assess property damages for targeting purposes may not be cost effective.

We study a model of time preference in which both current consumption and the memory of past consumption enter “experienced utility”—or the felicity—of an individual. An individual derives overall utility from her own felicity and the anticipated felicities of future selves. These postulates permit an agent to anticipate future regret in current decisions, and generate a set of novel testable implications in line with empirical evidence. The model can be applied to disparate phenomena, including present bias, equilibrium savings behavior, anticipation of regret, and career concerns.

Environmental nongovernmental organizations (NGOs) are increasingly using strategies to encourage firms to eliminate product components (e.g., palm oil) that are harmful to the environment (e.g., rainforests) or to replace them with NGO‐certified sustainable components. Under what conditions do NGOs’ information and ecolabeling strategies succeed in eliminating certain harmful components when these components contribute to the intrinsic quality of a product? The paper addresses these questions using a model of two‐dimensional vertical product differentiation in a market with consumers either informed or uninformed about the environmental quality of products and two firms that initially offer a product with the harmful component and a harmful component‐free product. We show that the information campaign plays a crucial and effective role in improving environmental quality, although the optimal share of informed consumers for the NGO is large but not always 100%. Ecolabeling cannot replace the information campaign. It is only a complementary tool to an intensive information campaign. Used together, they can succeed in triggering the substitution of the certified sustainable component for the harmful one.

Ce projet documente et analyse l’impact des aides à la décarbonation sur trois volets : le ciblage et le recours aux aides du plan France Relance, les effets économiques et environnementaux des précédentes vagues d’aides à la décarbonation et en particulier du Fonds Chaleur administré par l’Ademe, et les premiers effets rétrospectifs des impacts économiques des aides à la décarbonation du plan France Relance.

We explore differences in firms’ attitudes towards corporate social responsibility (CSR). Using a unique dataset covering 8,857 French firms, collected by the National Institute of Statistics and Economic Studies (INSEE), we identify firms conducting conscious CSR and others with effective but unaware CSR activities. We then construct three CSR pillar scores for each firm, using Mokken scale analysis, a form of non-parametric item response analysis. The CSR scores, along with responses to specific questions, allow us to characterize firms that implement conscious or unaware CSR. We then estimate simple probit and count data models to show that a significant share of firms are in fact actually engaged in unaware CSR, with no monotonic size effect. Cooperation with external actors such as NGOs mitigates the effect of firm size on the likelihood of conducting unaware CSR, while the effect of NGO campaigns against large firms is mainly to increase the environmental score of small firms in the same industry.

We study how regulating data usage impacts innovation in digital markets. Platforms commonly use proprietary data about third-party sellers to inform their own competing offerings, dampening incentives for innovation. We model this interaction and characterize how data usage restrictions reshape these incentives. An outright ban on data usage may boost or curtail innovation, depending upon the thickness of the right tail of demand for new products. More flexible rules controlling when and what data is made available can always improve the effectiveness of regulation. Our results contribute to an ongoing policy discussion regarding competition in digital markets.

In this paper, we investigate the Investor-State Dispute Resolution Settlement (ISDS) framework, which governs dispute resolution between foreign investors and host states in many bilateral and multilateral trade agreements. We show that ISDS delivers fair justice in a one-shot setting. In a repeated-interaction setting however, it is prone to collusion to the benefit of all parties except the host states. Three factors are determinant: First, the investors are the sole parties able to file cases; Second, arbitrators’ earning prospects depend on the investors’ filing cases; And finally, treaties leave substantial discretion to arbitration courts in their interpretation of treaties’ provisions. We give conditions for pro-business collusion between investors and arbitrators to develop and we show how it makes it profitable for foreign investors to file high-stake claims against states in response to new environmental, social or health regulations. Further, we address regulatory chill and show how the fear of ISDS attacks can hold back welfare improving regulation in the host country. Finally, we extend the model to show how regulatory chill affect policy-making in other countries in which the investor operates with similar activities.

Emission trading systems are cornerstone policies to reduce carbon emissions. Although economic intuition suggests that broader allowance trading should always be welfare improving, this paper proves that view can be wrong. Under an increasingly popular type of emissions trading scheme-tradable performance standards (TPS), multiple narrow markets can decrease emissions relative to a single unified market, so that restricting trade does not always harm welfare. We show analytically that, when intensity benchmarks are heterogeneous within a sector, this result can hold even if the well-known “implicit output subsidy” does not arise. Finally, we provide evidence that this concern is not a mere theoretical possibility but can actually be of high practical relevance. Using a general equilibrium model of China’s TPS for 2020-2030, we show that broader trading results in significantly higher emissions (up to 10%), and decreases welfare relative to narrower markets when the social cost of carbon exceeds $91/tCO2 .

L’urgence climatique n’est plus à démontrer : il est aujourd’hui nécessaire de modifier, pour les décarboner, toutes nos activités pro­ductives, nos métiers, et de réduire l’impact global de nos économies sur l’environnement. Cette transition d’ampleur est alternativement présentée comme le moyen de parvenir à une croissance verte créa­trice de richesses, ou comme un processus porteur d’une inévitable régression économique. Dépassant cette lecture clivée, Mireille Chiroleu-Assouline brosse un état des connaissances sur les effets de la transition énergétique, et plus largement écologique, en matière d’emploi. Elle montre que ce travail d’identification est un préalable indispensable à la mise en place de politiques macroéconomiques et d’accompagnement pour parvenir à une transition juste, qui ne s’accomplit pas aux dépens des personnes travaillant aujourd’hui dans les secteurs les plus polluants.

Modéliser la demande et les capacités de production d’énergie et de ressources minérales

This paper estimates the relationship between investments in five distributed generation technologies and hourly net withdrawals from over 2,000 electricity distribution networks in France between 2005 and 2018. We find that investments in distributed wind and solar generation have little or no impact on the annual peak of hourly net withdrawals from the distribution grid, while investments in hydroelectric and thermal distributed generation significantly reduce it. An optimistic analysis of the impact of investments in battery storage suggests that high levels are required for distributed wind and solar to deliver similar reductions in the annual peak of hourly net withdrawals. Our results imply that public policies favoring distributed wind and solar generation over utility-scale generation cannot be rationalized by savings in future grid investments. Code Jel L94 – Electric Utilities Q42 – Alternative Energy Sources Q48 – Government Policy

We analyze the effects of a debt relief, that is, a decrease in public debt of a low-income country financed by a high-income country, on environmental quality. Under perfect mobility of assets, the debt relief increases the overall capital stock, and environmental quality when public abatements are sufficiently efficient. Welfare in both countries can also improve. Under a weak mobility of assets, capital does no more increase in the richest country, but environmental quality can improve. This comes from a crowding-out effect of debt in the high-income country, which does no more take place when the mobility of assets is significant.

We review the literature on the academic publishing sector with a particular focus on the questions raised by open access. Dwelling on insights from the literatures on two-sided markets and certification, we discuss the various options to promote open access as well as possible policies to regulate the publishing market.

Regional scientific integration is a critical pathway for the development of an integrated African research area and knowledge-based society. On the African continent, progress in scientific production and integration has remained limited, mostly led by a global or international agenda, and bound to a few top publishing nations. The high-level policy commitments and the accumulated policies and strategies developed and pursued under the various intertwined sub-regional economic groupings have, to date, only diversely contributed to policy alignment and coordination in the area of science, technology, and innovation (STI) across Africa. In this context, this paper provides a first and hence original assessment of the role of region-specific factors in shaping scientific collaboration on the continent. For this purpose, our study builds upon the proximity approach to analyse the determinants of scientific collaboration between African countries, using co-publications data from Thomson Reuters’ Web of Science database as a proxy of such collaboration. Our results suggest that the majority of African regional economic communities (RECs) have not yet had a significant effect on scientific co-publication. Nevertheless, some important region-specific factors do seem to be at play, such as a shared ethnical language, membership in the African and Malagasy Council for Higher Education (CAMES), and the presence of a common European partner as a third partner in co-publication. Existing policies aimed at the development of an Africa-wide research area should aim to leverage existing and emerging regional excellence networks and novel coordination models to accelerate the process of scientific integration in Africa.

This paper examines the determinants of residential CO 2 emissions, which are not covered by the European Union Emissions Trading System (EU ETS), in 19 European countries between 2000-2017. Using both static and dynamic panel models, we found strong relationships between CO 2 emissions per capita, GDP per capita, energy prices and heating needs. We then assessed the impact of European carbon taxation and show that a e20/tonne CO 2 tax lowers emissions by 1% on average. We found that this tax affects countries differently in terms of tax revenue-to-GDP ratio. Poland and the Czech Republic would have to pay the highest contribution, and Portugal and Denmark the lowest. Finally, we propose a scenario that equalizes countries’ tax burdens. We show that, were Europe to redistribute all tax revenues, the main beneficiaries would be Poland and Belgium, while Denmark and Luxembourg would have to pay a surtax.

We explore differences in firms’ attitudes toward corporate social responsibility (CSR). Using a unique dataset covering 8,857 French firms, collected by the National Institute of Statistics and Economic Studies (INSEE), we identify firms conducting conscious CSR and others with effective but unaware CSR activities. We then construct three CSR pillar scores for each firm, using Mokken scale analysis, a form of non-parametric item response analysis. The CSR scores, along with responses to specific questions, allow us to characterize firms that implement conscious or unaware CSR. We then estimate simple probit and count data models to show that a significant share of firms are in fact significantly engaged in unaware CSR, with no monotonic size effect. Cooperation with external actors such as NGOs mitigates the effect of firm size on the likelihood of conducting unaware CSR, while the effect of NGO campaigns against large firms is mainly to increase the environmental score of small firms in the same industry.

This article studies the problem faced by activists who want to maximize firms’ compliance with high environmental standards. Our focus is on radical activism which relies on non-violent civil disobedience. The threat of disruptive actions is used to force firms to concede, i.e., to engage in self-regulation. We adopt a mechanism design approach to characterize an optimal campaign. The analysis indicates that the least vulnerable and most polluting firms should be targeted with disruptive actions while the others are granted a guarantee not to be targeted in exchange for concessions. This characterization allows us to study the determinants of the activist’s strength and how it is affected by repression, a central feature in civil disobedience. We find that an optimal campaign is relatively resilient to repression and that it creates incentives to free ride in the prosecution for individual firms. Next, we consider heterogeneity in firms’ abatement costs and find that an optimal campaign optimizes the allocation of abatement efforts and creates incentives for innovation. We discuss some other welfare properties of the optimal campaign.

Confronted with political opposition to the implementation of efficient carbon pricing, climate policy relies on alternative policy interventions, at a cost in terms of welfare and public finance. In order to evaluate this cost, this paper studies, in the context of the energy transition, second best climate policies constrained to keeping a constant level of the carbon tax and combining it with subsidies to carbon-free electricity generation. This subsidies can take the form of a feed-in premium paid to electricity produced from carbon-free sources, or of subsidies to investment in green capacity. Within a stylized dynamic model where energy may be produced with fossil or carbon-free sources and climate policy aims at satisfying a carbon budget, we define and characterize the carbon pricing gap. We show that if the constant carbon tax is small and therefore the carbon pricing gap large, the subsidy to carbon-free sources should be so large to foster rapid build up of green capacity that it would imply large investment costs and huge financial burden on the public budget, and a large welfare loss. We calibrate the model to the European energy market to obtain orders of magnitude of the effects.

We review the literature on the academic publishing sector with a particular focus on the questions raised by open access. Dwelling on insights from the literatures on two-sided markets and certification, we discuss the various options to promote open access as well as possible policies to regulate the publishing market.

Many public charging stations for electric vehicles in the United States are chargers installed at the premises of pre-existing businesses such as grocery stores or restaurants. This paper investigates the incentives of these retail businesses to install and operate charging stations. First, we note that observed pricing schedules for charging stations significantly depart from both first-best and monopoly pricing. We argue that a possible explanation is that many hosting facilities may install a charging station primarily as a strategy to attract more customers to their core business. Second, we use an imperfect competition model to study retail businesses’ incentives to invest in charging stations. We show that hosting facilities may be trapped in a prisoner’s dilemma where investing in a charging station decreases their profit in the long run. However, the equilibrium level of investments in public charging stations need not differ from the socially optimal outcome.

Cet article examine l’articulation entre les politiques environnementales et les politiques budgétaires et fiscales. Le financement des politiques environnementales représente un obstacle indéniable à leur mise en œuvre. Tout d’abord, l’efficacité des instruments standards de la politique environnementale est évaluée selon les critères de l’économie publique, notamment en termes de distorsions, externalités, bien-être et agrégats macroéconomiques. Les limites de ces instruments, quant à l’acceptabilité et aux inégalités, sont également envisagées. Par rapport aux quotas et aux normes, la taxe présente des avantages significatifs en termes d’incitations à des comportements plus vertueux, mais également en termes de revenus pour l’État. En limitant l’objectif de la taxe à la lutte contre les pollutions, le recyclage des recettes est un outil puissant de correction de ses effets indésirables. Néanmoins, face à un endettement excessif, les recettes de la taxe peuvent également servir au remboursement de la dette publique. Nous étudions ensuite les interactions entre la taxe environnementale et la dette publique. Le remboursement de la dette par les recettes de la taxe environnementale redonne des marges de manœuvre budgétaire. Symétriquement, en présence d’un niveau de dette acceptable, le financement des politiques publiques de lutte contre la pollution par l’émission de dette, sans augmentation de la pression fiscale, constitue une option intéressante. Néanmoins, le recours à la dette doit se faire avec parcimonie, seulement si la technologie de dépollution est significativement efficace. Enfin, la vulnérabilité environnementale des pays exposés au risque de transition ou climatique se traduit par le paiement d’une prime de risque sur leur dette souveraine, et donc par un surcoût de la dette publique, fragilisant d’autant plus les pays les plus pauvres. En conciliant les objectifs budgétaires et environnementaux, une remise de dette pour les pays en développement pourrait aider ces pays dans leur lutte contre la pollution.

International trade contributes directly to global greenhouse gas emissions, as the carbon content of high-emission products is priced differently in different countries. This phenomenon is termed carbon leakage. Thus, not putting a price on carbon is theoretically equivalent to an export subsidy, although that would be difficult to challenge in the context of multilateral trade law. Leakage can be alleviated by pricing the carbon embedded in imported products through a border carbon adjustment (BCA), be it a tax, a carbon tariff, or a regulation requiring the purchase of emissions allowances. The design of a BCA is a compromise between environmental effectiveness in preventing leakage, economic effectiveness in preserving competitiveness and ensuring acceptability, technical feasibility of the implementation, and World Trade Organization compatibility. An import-limited BCA is more effective than free emissions allowances in reducing leakage, but it does not preserve the export competitiveness of the country imposing it.

We consider optimal anonymous consumption taxes in situations where the magnitude of an externality varies with individuals who cause it. For instance, urban fuel consumers generate greater pollution damages compared to rural consumers, but both groups are subjected to the same fuel tax. We provide a condition for the validity of the targeting principle, where external concerns are only addressed through the tax imposed on the commodity responsible for the externality. When this condition holds, one can separate the equity/efficiency and environmental components of this tax. An illustration suggests that Pigovian considerations explain most of the fuel tax in France.

We study whether fiscal policies, especially public debt, can help to curb the macroeconomic and health consequences of epidemics. Our approach is based on three main features: we introduce the dynamics of epidemics in an overlapping generations model to take into account that old people are more vulnerable; people are more easily infected when pollution is high; public spending in health care and public debt can be used to tackle the effects of epidemics. We show that fiscal policies can promote convergence to a stable disease-free steady state. When public policies are not able to permanently eradicate the epidemic, public debt, and income transfers could reduce the number of infected people and increase capital and GDP per capita. As a prerequisite, pollution intensity should not be too high. Finally, we define a household subsidy policy that eliminates income and welfare inequalities between healthy and infected individuals.

Because they differ in terms of technology, size and location, solar photovoltaic installations exhibit very heterogeneous levelized costs of producing electricity. Therefore, the present value cost of meeting a given trajectory of annual solar energy production depends on which projects are commissioned when: the observed sequence of investment decisions need not be cost-efficient. We propose a methodology to assess dynamic misallocation by comparing the present value cost of realized investments to a counterfactual optimal sequence of investments. Applying our methodology to France between 2005 and 2021, we find that the observed trajectory of annual solar production could have been obtained at a present value cost almost 30% lower than its realized value. Our optimized counterfactual suggests that investments in residential solar should have on average been postponed by 7 years, while investments in medium and large-scale installations should have occurred 2 to 4 years earlier.

Confronted with political opposition to the implementation of efficient direct carbon pricing, climate policy relies on alternative policy interventions, such as subsidies to renewables. This paper uses a dynamic macroeconomic model under a carbon budget to study climate policies constrained to keeping a constant level of the carbon tax. We find that it is possible to implement the optimal trajectory by combing an increasing tax on electricity consumption with a feedin-premium paid to electricity produced from renewable sources. Otherwise, when the climate policy relies on the second instrument only, the subsidy to renewables should be so large to foster rapid build up of specialized capital, that it would imply large investment costs and financial burden on the public budget, unless the carbon tax level could be initially set at a high level. Unfortunately, the two solutions with no or low welfare losses raise concerns on their political acceptability too.

Confronted with political opposition to the implementation of efficient direct carbon pricing, climate policy relies on alternative policy interventions, such as subsidies to renewables. This paper uses a dynamic macroeconomic model under a carbon budget to study climate policies constrained to keeping a constant level of the carbon tax. We find that it is possible to implement the optimal trajectory by combing an increasing tax on electricity consumption with a feedin-premium paid to electricity produced from renewable sources. Otherwise, when the climate policy relies on the second instrument only, the subsidy to renewables should be so large to foster rapid build up of specialized capital, that it would imply large investment costs and financial burden on the public budget, unless the carbon tax level could be initially set at a high level. Unfortunately, the two solutions with no or low welfare losses raise concerns on their political acceptability too.

Two players receiving independent signals on a risky project with common value compete to be the first to invest. We characterize the equilibrium of this preemption game as the publicity of signals varies. Private signals create a winner’s curse: the first mover suspects that his rival might have privately received adverse information, hence exited. To compensate, players seek more evidence supporting the project, resulting in later investment. A conservative planner concerned with avoiding unprofitable investments may then prefer private signals. Our results suggest that policy interventions should primarily tackle winner-takes-all competition, and regulate transparency only once competition is sufficiently mild.

Renewable energy generation and storage requires specialized capital goods, embedding critical raw materials (CRM). The scarcity of CRM therefore affects the transition from a fossil based energy system to one based on renewables, necessary to cope with climate change. We consider the issue in a theoretical model, where we allow for a very costly potential substitute, reflecting a backstop technology, and for partial and costly recycling of materials in capital goods. We characterize the main features of the efficient energy transition, and their dependence on the relative abundance of CRM and on the recycling technology. Recycling reduces the cost of the transition. It also calls for having a large stock of recyclable CRM embedded in specialized capital at the time of adoption of the backstop technology. Moreover, we consider constraints on policy tools and myopic regulation, and show how abstracting from the scarcity of CRM, or tightly linking subsidies for renewables to the carbon tax revenue, is misleading in designing climate policy.

En près de dix ans d’existence, l’Association française des économistes de l’environnement et des ressources naturelles (Faere) a su fédérer une large population de chercheurs, tant français qu’étrangers, autour de problématiques qui sont plus que jamais au cœur des grands débats de nos sociétés. La conférence annuelle de l’association est l’occasion de discuter des développements les plus récents de ces recherches. Ce numéro de la Revue française d’économie propose un aperçu des travaux présentés lors de la conférence de 2021, organisée par l’université Grenoble Alpes et le GAEL.

We propose one of the first dynamic models of the optimal transition from fossil fuels to renewables in electricity generation that takes into account the variability and intermittency of renewable energy sources as well as storage. We take as an example solar energy, which is variable (no sun at night) and intermittent (few or no sun at day when there are clouds). We show that when the clouds phenomenon is not too severe, intermittency can be safely ignored and the planner just needs to take into account the deterministic variability of the renewable source. In this case, the optimal transition consists in using fossil fuels at day and night and complement them by solar electricity at day while investing to build up solar capacity; then abandoning fossils at day and keeping them for night electricity generation only; then, when solar capacity is large enough, starting to store electricity; and finally abandoning totally fossils when the carbon budget is exhausted. However, if the cloud problem is severe, intermittency matters a lot and precaution requires to start storage earlier, before fossils have been abandoned at day. We show that renewable electricity generation and storage are complement: absent storage devices, the long run solar capacity is smaller, and so is electricity consumption. We finally provide a quantitative illustration for the case of the Spanish energy transition. We show that in Spain intermittency can be safely ignored. We compute the carbon value corresponding to a 2 C carbon budget, the dates at which storage starts, and the path of investment in solar capacity.

We study the problem faced by activists who want to maximize firms’compliance with high environmental standards. Our focus is on radical activism which relies on non-violent civil disobedience. The threat of disruptive actions is used to force firms to concede i.e., to engage in self-regulation. We adopt a mechanism design approach to characterize an optimal campaign. The analysis informs that the least vulnerable and most polluting firms should be targeted with disruptive actions while the others are granted a guarantee not to be targeted in exchange for a concession. This characterization allows studying the determinants of the activist’s strength and how it is affected by repression, a central feature in civil disobedience. We find that an optimal campaign is relatively resilient to repression and that it creates incentives to free ride in prosecution for individual firms. Next, we consider heterogeneity in firms’abatement cost to find that an optimal campaign optimizes the allocation of abatment efforts and creates incentives for innovation. We discuss some other welfare properties of optimal campaign.

This paper contributes to the literature on firms’ export pricing by assessing whether and to what extent firms take into account the expected future evolution of the exchange rates while setting their prices. Using French micro-level trade data, our empirical analysis reveals that by adjusting their export prices, firms partly absorb information about future exchange rate variations. The extent to which individual exporters absorb future exchange rate fluctuations is found to depend on their market power, in accordance with theoretical dynamic demand-side models encompassing mechanisms creating an inter-temporal relationship between current market shares and future profits. The analysis also shows that the strength of such expectation-related mechanism is considerably reduced with greater future exchange rate uncertainty, in line with an interpretation of pricing-to-market as an investment decision under uncertainty. In a comparative perspective our results are shown to drive asymmetric responses across destinations of aggregate bilateral export flows to expected exchange rate movements.

We attempt to identify and measure knowledge spillovers in the French urban transport sector, which is strongly regulated and where a few large industrial groups are in charge of operating several urban networks. We build and estimate a structural cost model where the service is regulated by a local government and is provided by a single operator. Knowledge spillovers are directly linked to the know-how of a specific group, but they also depend on the incentive power of the regulatory contract which shapes the effort of the local managers. Exerting an effort in a specific network allows a cost reduction in this network, but it also benefits other networks that are members of the same group. We find that diversity of knowledge across operators of the same group improves absorptive capacity and increases the flow of spillovers. Simulation exercises provide evidence of significant reductions in total operating costs following the enlargement of industrial groups.

Confronted with political opposition to the implementation of efficient direct carbon pricing, climate policy relies on alternative policy interventions, such as subsidies to renewables. This paper uses a dynamic macroeconomic model under a carbon budget to study climate policies constrained to keeping a constant level of the carbon tax. We find that it is possible to implement the optimal trajectory by combing an increasing tax on electricity consumption with a feedin-premium paid to electricity produced from renewable sources. Otherwise, when the climate policy relies on the second instrument only, the subsidy to renewables should be so large to foster rapid build up of specialized capital, that it would imply large investment costs and financial burden on the public budget, unless the carbon tax level could be initially set at a high level. Unfortunately, the two solutions with no or low welfare losses raise concerns on their political acceptability too.

Climate variability has the potential to affect both international and internal migration profoundly. Earlier work finds that higher temperatures reduce agricultural yields, which in turn reduces migration rates in low-income countries, due to liquidity constraints. We test whether access to irrigation modulates this temperature–migration relationship, since irrigation buffers agricultural incomes from high temperatures. We regress measures of international and internal migration on decadal averages of temperature and rainfall, interacted with country-level data on irrigation and income. We find robust evidence that, for poor countries, irrigation access significantly offsets the negative effect of increasing temperatures on internal migration, as proxied by urbanisation rates. Our results demonstrate the importance of considering access to alternative adaptation strategies when analysing the temperature-migration relationship.

Reprendre en France la trajectoire de la taxe carbone suppose de surmonter les nombreux obstacles à son acceptation par la population. Cet article recense d’abord les arguments propres à convaincre le public de l’efficacité de la tarification du carbone pour réduire les émissions. Puis, sur la base de la littérature et à la lumière d’expériences internationales, il expose des propositions de mesures d’accompagnement propres à combattre les effets potentiellement défavorables sur l’emploi, à traiter les questions d’équité, à répondre au besoin de justice sociale, et à permettre de restaurer la confiance politique indispensable à l’acceptation de politiques climatiques efficaces.

This paper studies the consistency between two contradictory policies in the electricity industry. On the one hand, electricity systems are increasingly interconnected. On the other hand, reliability standards, whose value was typically set when countries were hardly interconnected, are still enforced at the national level. We show that enforcing autarky reliability standards may still reach the welfare optimum in the presence of interconnections, but only under two conditions. First, installed generation capacities should be determined jointly, while considering the whole power system. Second, reliability calculations should fully internalize external adequacy benefits occurring in neighboring systems. We run a numerical application for a set of European countries and find that existing interconnections may lead to generation adequacy benefits of around one billion euros per year, by enabling a 18.9 GW decrease in generation capacity. In our case study, regional coordination is found to be more important than fully internalizing external reliability benefits in adequacy simulations.

Cet article exploite l’abrogation de l’amendement Wright en 2014 aux États-Unis pour illustrer les conséquences d’un élargissement du marché pertinent sur la capacité des entreprises `a se coordonner sur un équilibre de Nash. A partir de données sur l’industrie du transport aérien, une procédure d’estimation en double-différences met en lumière la baisse de qualité ́e des prévisions des compagnies aériennes sur les marchés de Dallas après que des services longue distance impliquant l’aéroport Love Field ont été autorisés. Ce résultat suggère que les autorités de la concurrence devraient être prudentes lorsqu’elles se réfèrent à l’équilibre de Nash à la suite de réformes d’expansion du marché

Confronted with political opposition to the implementation of efficient direct carbon pricing, climate policy relies on alternative policy interventions, such as subsidies to renewables. This paper uses a dynamic macroeconomic model under a carbon budget to study climate policies constrained to keeping a constant level of the carbon tax. We find that it is possible to implement the optimal trajectory by combing an increasing tax on electricity consumption with a feedin-premium paid to electricity produced from renewable sources. Otherwise, when the climate policy relies on the second instrument only, the subsidy to renewables should be so large to foster rapid build up of specialized capital, that it would imply large investment costs and financial burden on the public budget, unless the carbon tax level could be initially set at a high level. Unfortunately, the two solutions with no or low welfare losses raise concerns on their political acceptability too.

The COVID-19 pandemic, its impact on the global economy, and current delays in the negotiation of the post-2020 global biodiversity agenda of the Convention on Biological Diversity heighten the urgency to build back better for biodiversity, sustainability, and well-being. In 2019 the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) concluded that addressing biodiversity loss requires a transformative change of the global economic system. Drawing on the IPBES findings, this policy perspective discusses actions in four priority areas to inform the post-2020 agenda: (1) Increasing funding for conservation; (2) redirecting incentives for sustainability; (3) creating an enabling regulatory environment; and (4) reforming metrics to assess biodiversity impacts and progress toward sustainable and just goals. As the COVID-19 pandemic has made clear, and the negotiations for the post-2020 agenda have emphasized, governments are indispensable in guiding economic systems and must take an active role in transformations, along with businesses and civil society. These key actors must work together to implement actions that combine short-term impacts with structural change to shift economic systems away from a fixation with growth toward human and ecological well-being. The four priority areas discussed here provide opportunities for the post-2020 agenda to do so.

Renewable energy generation and storage requires specialized capital goods, embedding critical raw materials (CRM). The scarcity of CRM therefore affects the transition from a fossil based energy system to one based on renewables, necessary to cope with climate change. We consider the issue in a theoretical model, where we allow for a very costly potential substitute, reflecting a backstop technology, and for partial and costly recycling of materials in capital goods. We characterize the main features of the efficient energy transition, and their dependence on the relative abundance of CRM and on the recycling technology. Recycling reduces the cost of the transition. It also calls for having a large stock of recyclable CRM embedded in specialized capital at the time of adoption of the backstop technology. Moreover, we consider constraints on policy tools and myopic regulation, and show how abstracting from the scarcity of CRM, or tightly linking subsidies for renewables to the carbon tax revenue, is misleading in designing climate policy.

We study whether fiscal policies, especially public debt, can help to curb the macroeconomic and health consequences of epidemics. Our approach is based on three main features: we introduce the dynamics of epidemics in an overlapping generations model to take into account that old people are more vulnerable; people are more easily infected when pollution is high; public spending and public debt can be used to tackle the effects of epidemics. We show that fiscal policies can promote the convergence to a stable steady state with no epidemics. When public policies are not able to permanently eradicate the epidemic, public debt and income transfers could reduce the number of infected people and increase capital and GDP per capita. As a prerequisite, pollution intensity should not be too high. Finally, we define a household subsidy policy which eliminates income and welfare inequalities between healthy and infected individuals.

We study whether fiscal policies, especially public debt, can help to curb the macroeconomic and health consequences of epidemics. Our approach is based on three main features: we introduce the dynamics of epidemics in an overlapping generations model to take into account that old people are more vulnerable; people are more easily infected when pollution is high; public spending and public debt can be used to tackle the effects of epidemics. We show that fiscal policies can promote the convergence to a stable steady state with no epidemics. When public policies are not able to permanently eradicate the epidemic, public debt and income transfers could reduce the number of infected people and increase capital and GDP per capita. As a prerequisite, pollution intensity should not be too high. Finally, we define a household subsidy policy which eliminates income and welfare inequalities between healthy and infected individuals.

Réussir notre transition énergétique vers un monde à zéro émissions nettes (ZEN) va être difficile et coûteux, mais nous n’avons pas le choix. Si nous voulons que la planète soit vivable pour nos enfants, nous devons basculer la production d’énergie depuis les sources fossiles vers les sources décarbonées et transformer l’économie. L’horloge climatique tourne très vite : une telle transition ne peut pas attendre. Progrès technologique, changement de préférences individuelles et de normes sociales, politiques fiscale et réglementaires, finance verte… – les leviers pour faire baisser les émissions de carbone sont nombreux. Certains sont plus efficaces, d’autres plus faciles à mettre en place, mais aucun, utilisé seul, ne peut être suffisant. Il nous faut les mobiliser tous, au sein d’un ensemble de mesures structuré autour d’un prix du carbone qui reflète la diminution du budget y afférant.

Ce texte s ’intéresse aux marches du seigle de la Corrèze en s’appuyant sur les mercuriales du département depuis le traité de libre- échange de 1860 jusqu’à la fin de la Grande Dépression Agricole en1896. De 1860 `a 1882, tous les marchés locaux sont intégrés et restent isolés des échanges commerciaux internationaux. Ils se retrouvent exposés `a partir de 1883 et se fragmentent : Brive et Tulle s’ancrent sur les grandes bourses internationales et se détachent d’Ussel.

This paper looks at the different strategies that two of the tire industry’s most prominent players, Pirelli and Michelin, deployed to exploit a radical process innovation: robotized, modular manufacturing. This paper argues that Pirelli, originally the technological follower, could develop a more nuanced, complex and ultimately successful strategy thanks to its superior knowledge integration capabilities. Empirically, we examine the structural characteristics and evolution of inventors’ networks in the two companies to reveal their knowledge integration capabilities. We apply the cohesive blocking method developed by White and Harary (Sociol Methodol 31(1):305–359, 2001) to argue that Pirelli, while relying on comparable skills in terms of technical fields, leveraged a more connected, cohesive and structured skills than Michelin. On this basis, it could develop and deploy a more complex strategy that better fit the characteristics of the new process technology. Pirelli’s knowledge network structure enhanced its knowledge integration capabilities and allowed for a more efficient fit between technology and strategy.

We attempt to identify and measure potential knowledge spillovers in the French urban transport sector, which is strongly regulated and where a few large corporations are in charge of operating several urban networks simultaneously. We build and estimate a structural cost model where the service is regulated by a local government and is provided by a single operator. Knowledge spillovers are directly linked to the know-how of a specific corporation, but they also depend on the incentive power of the regulatory contract which shapes the effort of the local managers. Exerting an effort in a specific network allows a cost reduction in this network, but it also benefit other networks that are members of the same corporation. Our model provides us with estimates of the operators’ absorptive capacity, which is their in-house knowledge power in order to optimally benefit from spillovers. We find that diversity of knowledge across operators of a same corporation improves absorptive capacity and increases the flow of spillovers. Simulation exercises provide evidence of significant reductions in total operating cost following the enlargement of industrial groups.

This article shows that two widely used data sources from the French military administration pertain to two different enlistment stages and combines these sources to build a quasi-exhaustive panel of young men around their 20s. The panel is applied to measure height growth of men born at the end of the 19th century in an economically backward small rural area of France. The one-year growth is 0:39cm and only concerns the shortest men; the tallest men already reached adult maturity. Industrial pollution imposes a growth penalty that overcomes the enhancing impact of industrial development.

We examine an open economy’s strategy to reduce its carbon emissions by replacing its consumption of coal—very carbon intensive—with gas—less so. Unlike the standard theoretical approach to carbon leakage, we show that unilateral CO2 reduction policies generate a higher leakage rate in the presence of more than one carbon energy source and may turn counterproductive, ultimately increasing world emissions. We establish testable conditions as to whether a unilateral tax on domestic CO2 emissions increases the domestic exploitation of gas and whether such a strategy increases global emissions. We also characterize this strategy’s implications for climate policy in the rest of the world. Finally, we present an illustrative application of our results to the United States.

Although a carbon value has often been integrated in the frameworks established to guide public decision-making, benefit-cost analysis (BCA) has played no more than a minor role in the design of climate policies. It is urgently necessary to promote BCA in this area, and there is currently a unique opportunity for doing so. Major countries are designing new packages in order to meet their commitments, as illustrated by the European Green Deal, recent decisions on the part of the Biden Administration, and the creation of a Chinese national carbon market. These constructive processes must be based on BCA. BCA is absolutely necessary in order to achieve net-zero emissions by 2050 at a reasonable cost. Indeed, abatement costs across and within sectors, and across and within countries, are extremely heterogeneous, and many of the policy instruments in use (subsidies, feed-in tariffs, technical standards, etc.) overlap inefficiently. The instrumental debate between carbon pricing and other instruments is sterile if it merely remains at the level of stating principles. BCA can help on this point too, by specifying comparisons between alternatives, identifying complementarities, and selecting the most relevant combinations of instruments. Its scope should therefore range from setting benchmarks for carbon pricing to assessing, e.g., green investments or measures to enhance carbon sinks. When applied to decarbonization policies, BCA requires firstly the selection of a carbon value, in order to monetize the climate benefits of investments and policies. However, the whole assessment framework must be updated, including the time horizon, the discount rate, the cobenefits of climate mitigation actions, and the pricing of climate risks. We show that such an updated framework leads to an upward revision in the assessment of the climate benefits of mitigation actions, and that combining the valuation of damages and cost-effectiveness approaches is necessary in order to meet the needs of policy assessment. Finally, there is a need to extend analysis beyond the efficiency criterion in order to deal with other dimensions of climate policies, particularly their distributive impacts. This requires specific analyses, which should be articulated with BCA and carried out at an early stage for a better implementation of climate policies than we have seen to date.

Migration is a common means of adaptation to weather shocks. Previous research has identified heterogeneous effects according to age, sex, and wealth, but little is still known about how marriage-related institutions affect such migration. Relying on a quasi-experimental identification strategy, we analyze marriage- and work-related migration in Malawi following large droughts, separating the effects for female and male migrants according to different age groups. The analysis based on stated motives of migration reveals marginal decreases in marriage-related migration among girls, but increases in marriage-related migration within districts for women in older age groups. We also find large increases in work-related between-district migration for boys, and to a smaller extent also for girls following severe drought. The results add to the evidence of the potentially adverse effects of migration as a coping mechanism following drought when other means of insurance do not exist.

This paper presents a first model integrating the relation between biodiversity loss and zoonotic pandemic risks in a general equilibrium dynamic economic set-up. The occurrence of pandemics is modeled as Poissonian leaps in economic variables. The planner can intervene in the economic and epidemiological dynamics in two ways: first (prevention), by deciding to conserve a greater quantity of biodiversity to decrease the probability of a pandemic occurring, and second (mitigation), by reducing the death toll through a lockdown policy, with the collateral effect of affecting negatively labor productivity. The policy is evaluated using a social welfare function embodying society’s risk aversion, aversion to fluctuations, degree of impatience and altruism towards future generations. The model is explicitly solved and the optimal policy described. The dependence of the optimal policy on natural, productivity and preference parameters is discussed. In particular the optimal lockdown is more severe in societies valuing more human life, and the optimal biodiversity conservation is larger for more “forward looking” societies, with a small discount rate and a high degree of altruism towards future generations. Moreover, societies accepting a large welfare loss to mitigate the pandemics are also societies doing a lot of prevention. After calibrating the model with COVID-19 pandemic data we compare the mitigation efforts predicted by the model with those of the recent literature and we study the optimal prevention–mitigation policy mix.

This article addresses the issue of favoritism at the design stage of a complex procurement auction. A community of citizens procures a project but lacks the ability to translate its preferences into operational technical specifications. This task is delegated to a public officer who may collude with one of the firms in exchange of a bribe. We investigate a simple accountability mechanism that requires justifying one aspect of the technical decision determined by the alerts of competitors (alert-based accountability [ABA]). We find that relying on competitors enables the community to deter favoritism significantly more easily than random challenges. The penalty needed to fully deter corruption is independent of the complexity of the project. It depends on the degree of differentiation within the industry. In an illustrative example, we study the patterns of favoritism when corruption occurs under ABA and compare them with the patterns in the random challenge mechanism.

We study a bilateral trade setting in which a buyer has private valuations over a multi-product seller’s inventory. We introduce the notion of an incentive-compatible market segmentation (IC-MS)—a market segmentation compatible with the buyer’s incentives to voluntarily reveal their preferences. Our main result is a characterization of the buyer-optimal IC-MS. It is partially revealing, comprised primarily of pooling segments wide enough to keep prices low but narrow enough to ensure trade over relevant products. We use our results to study a novel design problem in which a retail platform seeks to attract consumers by calibrating the coarseness of its search interface. Our analysis speaks directly to consumer privacy and the debate regarding product steering versus price discrimination in online retail.

How can decentralized individual decisions inefficiently reduce the ability of biodiversity to mitigate ecological and environmental variability and then its “natural insurance” role? In this article we present a simple theoretical setup to address this question and to evaluate some policy options. We study a model of strategic competition among farmers for the conversion of a natural forest to agricultural land. Unconverted forest land allows to conserve biodiversity, which contributes to reducing the volatility of agricultural production. Agents’ utility is given in terms of a Kreps Porteus stochastic differential utility capable of disentangling risk aversion and aversion to fluctuations. We characterize the land used by each farmer and her welfare at the Nash equilibrium, we evaluate the overexploitation of the land and the agents’ welfare loss compared to the socially optimal solution and we study the drivers of the inefficiencies of the decentralized equilibrium. After characterizing the value of biodiversity in the model, we use it to obtain a decomposition which helps to study the policy implications of the model by identifying in which cases the allocation of property rights is preferable to the introduction of a tax on land conversion. Our results suggest that enforcing property rights is more relevant in case of stagnant economies while taxing land conversion may be more suited for rapidly developing economies.

Ce texte s’intéresse aux marchés du seigle de la Corrèze en s’appuyant sur les mercuriales du département depuis le traité de libre-échange de 1860 jusqu’à la fin de la Grande Dépression Agricole en 1896. De 1860 à 1882, tous les marchés locaux sont intégrés et restent isolés des échanges commerciaux internationaux. Ils se retrouvent ex- posés à partir de 1883 et se fragmentent : Brive et Tulle s’ancrent sur les grandes bourses internationales et se détachent d’Ussel.

This paper assesses the usefulness of stochastic contracts in the presence of informational asymmetries. It identifies circumstances where a stochastic redistribution policy is socially dominated by the deterministic policy where after-tax income lotteries are replaced with their certainty equivalent. It also provides a parametric example where every stochastic menu which has the optimal deterministic menu as certainty equivalent is dominated by the deterministic menu, while there exist feasible and incentive compatible lotteries improving locally upon the deterministic menu.

This paper exploits the repeal of the Wright amendment as a natural experiment in order to contribute to the ongoing discussion on how the enlargement of the relevant market affects the ability of firms to coordinate on a Nash equilibrium. Using data on the U.S. air transportation industry, we present a Difference-inDifference procedure which sheds light on the significant loss of accuracy in airlines’ predictions in markets originating in Dallas after the Love Field airport started operating long distance services in 2014. This suggests that competition authorities should be careful when they refer to the Nash equilibrium following market expansion reforms.

Introduction to IIPF 2020 special issue in ITAX: reflections on the interactions between environmental economics and public finance

We review some of the recent estimates of the effect of weather and climate on migration, and articles examining the historical evidence of such links. We identify four issues that have received less attention in previous reviews on the topic. The first one is general equilibrium effects of climate change and migration. The second one concerns accounting for thresholds in the climate-migration relationship. Some of the articles that we review incorporate non-linear effects, but only in the relation between income and migration, and in the relation between weather, climate and migration. Other thresholds are not yet incorporated into the literature. A third issue where much work remains to be done relates to climate change and conflict, and their influence on migration. Finally, we conclude with some reflections on the implications of the results for economic development.

We examine the effect of flood risk regulation on property prices in the inner suburbs of Paris, France. Increased flood risk is one of the major consequences of climate change, and it is already a current risk for populations in some areas of Southern and Western France. The Ile-de-France region is highly exposed to the risk of a major flood of the Seine River. About 830 000 people and 620 000 jobs would be directly affected if a flood similar to the historic event of 1910 would occur (IAU, 2011; OECD,2013). A large literature has examined the impact of actual floods with a surprisingly large variation in results. Only a few studies have investigated the effect of information about flood risk (Harrison et al., 2001; Troy and Romm, 2004; Hallstrom and Smith, 2005; Pope, 2008; Rajapaksa et al., 2016), as opposed to the direct economic impact of flood damage. It is not easy to separate the effect of information on flood risk, as such, as flood prone areas by definition also are likely to suffer recurrent flooding. Since a major role of flood risk regulation is to inform actors in the real estate markets about the actual risk, it is important for policy purposes to evaluate the reaction to information on flood risk separately from any damage from actual floods. The inner suburbs around Paris offer a unique opportunity to do so, since there is high flood risk, but no major flood occurred during the period analysed in the paper. In this article, we study the impact of information on flood risk released through the implementation of the French regulation on flood risk prevention plans (PPRi). The objective of the paper is to test whether information on flood risk has an impact on the price of the real estate transactions in the inner suburbs of Paris over the period 2003 to 2012. During the period, it can be assumed that past flood events were not salient to buyers and sellers in the region, since the last major flood of the Seine river at the time was the 50-year flood of 1955. The more recent ten-year floods of 2016 and 2018 occurred after the period of the study. This avoids a confounding direct effect on prices of flood itself and permits us to argue that we identify only an effect of flood risk information on price.

We examine the effect of flood risk regulation on property prices in the inner suburbs of Paris, France. Increased flood risk is one of the major consequences of climate change, and it is already a current risk for populations in some areas of Southern and Western France. The Ile-de-France region is highly exposed to the risk of a major flood of the Seine River. About 830 000 people and 620 000 jobs would be directly affected if a flood similar to the historic event of 1910 would occur (IAU, 2011; OECD,2013). A large literature has examined the impact of actual floods with a surprisingly large variation in results. Only a few studies have investigated the effect of information about flood risk (Harrison et al., 2001; Troy and Romm, 2004; Hallstrom and Smith, 2005; Pope, 2008; Rajapaksa et al., 2016), as opposed to the direct economic impact of flood damage. It is not easy to separate the effect of information on flood risk, as such, as flood prone areas by definition also are likely to suffer recurrent flooding. Since a major role of flood risk regulation is to inform actors in the real estate markets about the actual risk, it is important for policy purposes to evaluate the reaction to information on flood risk separately from any damage from actual floods. The inner suburbs around Paris offer a unique opportunity to do so, since there is high flood risk, but no major flood occurred during the period analysed in the paper. In this article, we study the impact of information on flood risk released through the implementation of the French regulation on flood risk prevention plans (PPRi). The objective of the paper is to test whether information on flood risk has an impact on the price of the real estate transactions in the inner suburbs of Paris over the period 2003 to 2012. During the period, it can be assumed that past flood events were not salient to buyers and sellers in the region, since the last major flood of the Seine river at the time was the 50-year flood of 1955. The more recent ten-year floods of 2016 and 2018 occurred after the period of the study. This avoids a confounding direct effect on prices of flood itself and permits us to argue that we identify only an effect of flood risk information on price.

We study competition in the U.S. airline industry relaxing the Nash equilibrium assumption that airlines are able to predict perfectly the behavior of their competitors. We assess empirically whether an equilibrium is more likely to occur if it is the unique rationalizable outcome. We find that equilibria of short distance routes with high traffic and low concentration are the most fragile, and low-cost companies appear detrimental to their occurrence. Our analysis is applied to the measurement of welfare gains from firms’ entry, and to the characterization of the relevant market when some products are unobserved.

This paper explores how insurance companies can coordinate to extend their joint capacity for the coverage of new and undiversifiable risks. The undiversifiable nature of such risks causes a shortage of insurance capacity and their limited knowledge makes learning and information sharing necessary. We develop a unified theoretical model to analyse co-insurance agreements. We show that organizing this insurance supply amounts to sharing a common value divisible good between capacity constrained and privately informed insurers with a reserve price. Coinsurance via the creation of an insurance pool turns out to operate as a uniform price auction with an “exit/re-entry” option. We compare it to a discriminatory auction for which no specific agreements are needed. Both auction formats lead to different coverage/premium tradeoffs. If at least one insurer provides an optimistic expertise about the risk, the pool offers higher coverage. This result is reversed when all insurers are pessimistic about the risk. Static comparative results with respect to the severity of the capacity constraints and the reserve price are provided. In the case of completely new risks, a regulator aiming at maximizing the expected coverage should promote the pool when the reserve price is low enough or when competition is high enough.

The literature on special interest groups emphasizes two main influence channels: campaign contributions and informational lobbying. We introduce a third channel: providing information about the credibility of political rivals. In particular, nongovernmental organizations (NGOs) often aim to communicate scientific knowledge to policymakers, but industry‐backed groups often attempt to undermine their credibility. We extend a standard signaling model of interest‐group lobbying to include fixed costs of policymaker action and show that these costs make possible two mechanisms for creating doubt about the value of policy action. The first uses Bayesian persuasion to suggest the NGO may be a noncredible radical. The second involves creating an opposition think tank (TT) that acts as a possible radical, not a credible moderate. We show that the TT cannot always implement the Bayesian persuasion benchmark, and we characterize how optimal TT design varies with exogenous parameters.

Among the ten countries with the highest carbon intensity, six are natural resource-rich countries. This suggests the existence of a carbon curse: resource-rich countries would tend to follow more carbon-intensive development paths than resource-poor countries. We investigate this assumption empirically using a panel data method covering 29 countries (OECD and BRIC) and seven sectors over the 1995-2009 period. First, at the macroeconomic level, we find that the relationship between national CO 2 emissions per unit of GDP and abundance in natural resources is U-shaped. The carbon curse appears only after the turning point. Second, we measure the impact of resource abundance on sectoral emissions for two groups of countries based on their resource endowments. We show that a country rich in natural resources pollutes relatively more in resource-related sectors as well as all other sectors. Our results suggest that the debate on climate change mitigation should rather focus on a comparison of resource-rich countries versus resource-poor countries than the developed-country versus developing-country debate.

The production of energy from renewable sources is much more intensive in minerals than that from fossil resources. The scarcity of certain minerals limits the potential for substituting renewable energy for scarce fossil resources. However, minerals can be recycled,while fossil resources cannot. We develop an intertemporal model to study the dynamics of the optimal energy mix in the presence of mineral intensive renewable energy and fossil energy. We analyze energy production when both mineral and fossil resources are scarce,but minerals are recyclable. We show that the greater the recycling rate of minerals, the more the energy mix should rely on renewable energy, and the sooner should investment in renewable capacity take place. We confirm these results even in the presence of other better known factors that affect the optimal schedule of resource use: expected productivity growth in the renewable sector, imperfect substitution between the two sources of energy, convex extraction costs for mineral resources and pollution from the use of fossil resources.

We study the problem faced by activists who want to maximize …rms’compliance with high environmental standards. Our focus is on radical activism which relies on non-violent civil disobedience. Disruptive actions and the threat thereof are used to force …rms to concede i.e., to engage in self-regulation. We address the optimal use of scarce activist resources in face of incomplete information by looking at a general mechanism, directly adapted from Myerson’s (1981) optimal auction theory. The characterization informs that the least vulnerable and most polluting …rms should be targeted with disruptive actions while the others are granted a guarantee not to be targeted in exchange for a concession. This characterization allows studying the determinants of the activist’s strength and how it is a¤ected by repression, a central feature for civil disobedience. We …nd that optimal radical activism is relatively resilient to repression. In an extension that accounts for asymmetry between …rms’abatement cost, we …nd that the mechanism optimizes the allocation of abatment efforts and creates incentives for innovation. We discuss some other welfare properties of optimal activism.

Non-governmental organizations (NGOs) are exerting growing pressure on firms to eliminate product components (such as palm oil) that are harmful to the environment (such as rainforests) or replace such components with NGO-certified sustainable components. Under which conditions does NGO pressure lead firms to eliminate basic components from their products or, alternatively, substitute damaging components with certified sustainable components? What are the ensuing effects on market structure, environmental quality, and social welfare? The paper addresses these issues using a model of two-dimensional vertical product differentiation. It shows that, for an NGO that collects certification fees to accrue its budget and finance its awareness campaign, it may — paradoxically — be optimal to reduce the certified product’s market share and eventually evict it.

Nous étudions les limites de la redistribution qu’impliquent les asymétries d’information entre la puissance publique et les assujettis dans un modèle de fiscalité optimale mêlant un impôt direct sur le revenu et des impôts indirects sur la consommation. En utilisant l’enquête Budget de Famille 2011, nous trouvons que la puissance publique souhaiterait favoriser les ménages de la classe moyenne aisée situés aux alentours du sixième décile de la distribution des dépenses par unité de consommation. L’innovation de ce texte est de montrer que la redistribution en leur faveur est freinée par le risque que les ménages des classes supérieures, situés dans le dernier quartile de la distribution des dépenses, relâchent leur contribution à l’effort productif.

The Coronavirus pandemic is imposing tremendous health impacts around the world. At the time of writing (20th July 2020) there have been nearly 15 million cases worldwide and well over half a million deaths from the Covid-19 disease caused by the virus. The fact that this statement needs to be effectively date-stamped reflects the rapid development of this pernicious virus. While several vaccines are under rapid development, so far it is unclear if any will be truly effective given the ability of the virus to mutate; already the vast majority of Covid-19 cases are caused by a virus which is no longer identical to that which appeared in Wuhan in late 2019.

We explore firms’ commitment to Corporate Social Responsibility (CSR). Using a unique dataset of 8,857 French firms collected through a survey conducted at the end of 2011 by the French National Institute of Statistics and Economic Studies (INSEE), we first construct 3 CSR pillar scores for each firm, based on a non-parametric Item Response Theory model known as Mokken Scale Analysis. CSR scores, along with responses to specific items of the 2011 INSEE survey, allow us to characterize firms implementing formal versus informal CSR. We then estimate simple probit models and count data models to show that, with regards to CSR commitment, size definitely matters, and that a significant share of firms stating that they are not actively committed to CSR, actually engage significantly in CSR, with no monotonic size effect. Cooperation with external actors such as NGOs mitigates the size effect in the likelihood of carrying out informal CSR, whereas the pressure of NGO campaigns against large companies mainly spurs the environmental score of smaller firms in the same sector.

This article analyzes the impacts of debt relief on production and pollution. We develop a two-country overlapping generations model with environmental externalities, public debts and perfect mobility of assets. Pollutant emissions arise from production, but agents may invest in pollution mitigation. Could debt relief be an efficient tool to encourage less developed countries to engage in the fight against climate change? We consider a decrease of the debt of the poor country balanced by an increase of the richer country’s debt. We show that debt relief makes it possible to engage poor countries in the process of pollution abatement. Capital, environmental quality and welfare can increase in both countries. This result relies on the environmental sensitivity and the discount factor in the poor country relative to the rich one: the greater they are the more beneficial the debt relief is.

This article analyzes the impacts of debt relief on production and pollution. We develop a two-country overlapping generations model with environmental externalities, public debts and perfect mobility of assets. Pollutant emissions arise from production, but agents may invest in pollution mitigation. Could debt relief be an efficient tool to encourage less developed countries to engage in the fight against climate change? We consider a decrease of the debt of the poor country balanced by an increase of the richer country’s debt. We show that debt relief makes it possible to engage poor countries in the process of pollution abatement. Capital, environmental quality and welfare can increase in both countries. This result relies on the environmental sensitivity and the discount factor in the poor country relative to the rich one: the greater they are the more beneficial the debt relief is.

The paper examines the effect of flood risk regulation on property prices in the inner suburbs of Paris, France, over the period 2003 to 2012. We use unique data on property transactions and geo-localised amenities from a major European city exploiting the different dates of implementation of the flood risk zone regulation. Using an identification strategy based on a difference-in-differences specification, the results indicate that home prices for similar real estate are 3 to 7% lower when located in a flood risk zone, depending on the sub market (flats or houses). The discount is higher, the higher is the flood risk designated by the regulation. Buyers’ previous exposure to floods reduces the price discount.

The paper examines the effect of flood risk regulation on property prices in the inner suburbs of Paris, France, over the period 2003 to 2012. We use unique data on property transactions and geo-localised amenities from a major European city exploiting the different dates of implementation of the flood risk zone regulation. Using an identification strategy based on a difference-in-differences specification, the results indicate that home prices for similar real estate are 3 to 7% lower when located in a flood risk zone, depending on the sub market (flats or houses). The discount is higher, the higher is the flood risk designated by the regulation. Buyers’ previous exposure to floods reduces the price discount.

This paper investigates the distributional and efficiency consequences of an environmental tax reform that distributes the revenue from a green tax according to varying labour tax rates. We build a general equilibrium model with heterogeneous workers, imperfect labour markets (search and match), and pollution consumption externalities. Preferences are non-homothetic (Stone-Geary utility) to take into account the potential regressivity of green taxes (the polluting good is assumed to be a necessary good). If the reform appears regressive, the gains from the double dividend can achieve Pareto improvement, using a redistributive non-linear income tax if the redistribution is not too great initially. Increasing progressivity influences the unemployment rate and can moderate the trade-off between equity and efficiency. We finally provide numerical illustrations for France and conduct sensitivity analysis.

Cette note étudie comment un choc de demande exogène, tel que des aides publiques, influence le potentiel d’exclusion contenu dans les effets d’apprentissage. Nous construisons un modèle de duopole à deux périodes dans lequel l’accroissement de production par une entreprise à la première période fait baisser son coût marginal de production à la seconde. Nous étudions ensuite un premier scénario dans lequel la demande et le processus d’apprentissage sont linéaires pour montrer qu’un choc positif de demande amplifie l’effet d’exclusion de l’apprentissage si et seulement si les entreprises sont suffisamment asymétriques en termes de capacités d’apprentissage. Dans un second scénario, les entreprises sont infiniment impatientes, ce qui permet de mettre en lumière le rôle clé joué par la courbure de la fonction de demande dans le potentiel d’exclusion des effets d’apprentissage à la suite d’un choc de demande.

Voluntary standards certifying environmental qualities of labeled products have proliferated across sectors and countries. Effectuating these standards requires the collaboration among and between creators (typically firms and nongovernmental organizations) and adopters (firms across a particular supply chain). However, the need to collaborate does not rule out the presence of controversy. Drawing on the case of the Marine Stewardship Council, a leading seafood standard to conserve the world’s threatened marine fauna, we analyze how this controversy, from economic and sociologic vantage points, impacts a sustainability transition. In essence, interest divergence drives controversy over standard design, which spurs controversy over standard effectiveness and prompts the proliferation of competing standards. Controversy is magnified by the opacity or nontransparency of the fields which such standards seek to govern. We conclude that, while interest divergence and field opacity entail inherent controversy over voluntary environmental standards, the impact of this controversy on sustainability transitions is typically predominantly positive.

We use the Targeted Subsidies Reform implemented in Iran in 2011 to recover empirically the social valuations of Iranian households relying on the assumption of optimal consumption and income taxes, for welfarist and non-welfarist poverty alleviation social criteria. Unlike the existing literature, we do not restrict attention to a specific pattern for the incentive constraints implied by nonlinear income taxation. Instead we recover this pattern by estimating the Lagrange multipliers associated with the incentive constraints. Before the reform we find evidence of redistribution toward the bottom poor income deciles that is limited by an incentive constraint where the rich envy the social treatment of the poor. At the outcome of the reform incentives no longer matter and the social welfare function of the government of Iran displays a Benthamite-like form.

Consider a simple general equilibrium economy with one representative consumer, a single competitive firm and the government. Suppose that the government has to finance public expenditures using linear consumption taxes and/or a lump-sum tax on profits redistributed to the consumer. We show that, if the tax rate on profits cannot exceed 100 percent, one cannot improve upon the second-best optimum of an economy with constant returns to scale by using a less efficient profit-generating decreasing returns to scale technology.

The paper examines the effect of flood risk regulation on property prices in the inner suburbs of Paris, France, over the period 2003 to 2012. We use unique data on property transactions and geo-localised amenities from a major European city exploiting the different dates of implementation of the flood risk zone regulation. Using an identification strategy based on a difference-in-differences specification, the results indicate that home prices for similar real estate are 3 to 7% lower when located in a flood risk zone, depending on the sub market (flats or houses). The discount is higher, the higher is the flood risk designated by the regulation. Buyers’ previous exposure to floods reduces the price discount.

We propose an aggregate growth index that explicitly accounts for fat tails in the firm size distribution and for the negative scaling relation between the size of the firm and the volatility of its growth rates. Using Compustat data on US publicly traded company, we show that the new index tracks aggregate fluctuations much better than simpler measures of central tendency of the dynamics of firms, like the growth rates sample average, confirming that the statistical properties characterizing the micro-economic dynamics of firms are relevant for the dynamics of the aggregate. To better characterize the origins of aggregate fluctuations, we decompose the index in two parts, describing, respectively, the modal (typical) value of log growth rates and the tilt (asymmetry) of their distribution. Regression analysis shows that models based on this decomposition, despite their simplicity, possess a remarkable explanatory and predictive power with respect to the aggregate growth.

Observing that most social networks are clustered, the literature often argues that agents are more willing to form links that close triangles. We challenge this idea by proposing a simple model of new collaboration formation that shows why network clustering may arise even though agents do not “like” network closure. We address empirically this question on the longitudinal evolution of the French co-invention network, and find that two inventors are less likely to form a first research collaboration when they have common partners. Our findings further reveal the preferences of inventors towards forming non-redundant connections.

This paper presents a benchmark stochastic endogenous growth model of an agricultural economy. Producing food requires land, and increasing the share of total land devoted to farming mechanically reduces the share of land devoted to biodiversity conservation. However, safeguarding a greater number of species guarantees better ecosystem services, which in turn ensure lower volatility of agricultural productivity. The optimal conversion/conservation rule is explicitly characterized. Value of biodiversity is considered in its function of hedging against the volatility of agricultural production. Two aspects of biodiversity’s value are examined. We first consider the total value of biodiversity as the welfare gain from biodiversity conservation, that is, the percentage increase in consumption that the society is willing to accept to give up the optimal level of biodiversity in favor of no biodiversity at all. We then consider the insurance value of biodiversity, extending the usual concepts to our stochastic dynamic framework, defining the insurance value of biodiversity as the change of the risk premium due to a marginal change in the level of biodiversity. To highlight the impact of risk on the optimal decision as in the value of biodiversity, we use the Epstein-Zin-Weil specification of preferences and represent preferences by a recursive utility function. This allows us to disentangle the effects of risk aversion and aversion to fluctuations. Thus, the preference for some rather uncertain outcomes and the propensity to smooth consumption over time are represented by two distinct parameters, and the effect of each of them are studied.

Migration is one response to climatic stress and shocks. In this article we review the recent literature across various disciplines on the effects of climate change on migration. We explore key features of the relationship between climate change and migration, distinguishing between fast-onset and slow-onset climatic events and examining the causes of heterogeneity in migratory responses to climate events. We also seek to shed light on the interactions between different types of adaptations to climate events as well as the mechanisms underlying the relationship between climate change and migration. Based on our review of the existing literature, we identify gaps in the literature and present some general policy recommendations and priorities for research on climate-induced migration.

We introduce nine papers on sustainable resource dynamics. In addition, we provide analytical results on the effect of stochastic damages on optimal economic growth, the effects of habits and loss aversion on the cost-benefit discount rate, and the effect of a carbon budget and carbon capture and storage (CCS) on optimal investment in technical change.

We examine the effect of flood risk regulation on property prices in the inner suburbs of Paris, France. Increased flood risk is one of the major consequences of climate change, and it is already a current risk for populations in some areas of Southern and Western France. The Ile-de-France region is highly exposed to the risk of a major flood of the Seine River. About 830 000 people and 620 000 jobs would be directly affected if a flood similar to the historic event of 1910 would occur (IAU, 2011; OECD,2013). A large literature has examined the impact of actual floods with a surprisingly large variation in results. Only a few studies have investigated the effect of information about flood risk (Harrison et al., 2001; Troy and Romm, 2004; Hallstrom and Smith, 2005; Pope, 2008; Rajapaksa et al., 2016), as opposed to the direct economic impact of flood damage. It is not easy to separate the effect of information on flood risk, as such, as flood prone areas by definition also are likely to suffer recurrent flooding. Since a major role of flood risk regulation is to inform actors in the real estate markets about the actual risk, it is important for policy purposes to evaluate the reaction to information on flood risk separately from any damage from actual floods. The inner suburbs around Paris offer a unique opportunity to do so, since there is high flood risk, but no major flood occurred during the period analysed in the paper. In this article, we study the impact of information on flood risk released through the implementation of the French regulation on flood risk prevention plans (PPRi). The objective of the paper is to test whether information on flood risk has an impact on the price of the real estate transactions in the inner suburbs of Paris over the period 2003 to 2012. During the period, it can be assumed that past flood events were not salient to buyers and sellers in the region, since the last major flood of the Seine river at the time was the 50-year flood of 1955. The more recent ten-year floods of 2016 and 2018 occurred after the period of the study. This avoids a confounding direct effect on prices of flood itself and permits us to argue that we identify only an effect of flood risk information on price.

We study the optimal design of consumption taxes when both global and local externalities matter. Local externalities make the social impact of the consumption of externality-generating commodities varying across consumers. A typical example involves the greater damage caused by pollution from urban fuel consumers. We provide a condition for the validity of the targeting principle according to which externality concerns should only fall on the taxes on externality-generating commodities. When this condition is satisfied, one can decompose the tax on an externality-generating commodity into equity/efficiency and Pigovian contributions. The Pigovian contribution should exceed the average social damage if the fuel consumption of the greatest polluters is more responsive to fuel price. In an empirical illustration we find that the fuel tax in France is mostly explained by Pigovian considerations.

We study optimal linear commodity taxes in the presence of non-linear income taxes when agents differ in skills and tastes for consumption. We show that optimal commodity taxes are partly determined by a many-person Ramsey rule when there is taste heterogeneity within income classes. The usual role of commodity taxes in relaxing incentive constraints explains the remaining part of these taxes when there is taste heterogeneity between income classes. We quantify these two parts using French consumption microdata and find that commodities taxes are only shaped by many-person Ramsey considerations.

This paper studies fiscal competition under the origin principle. It identifies a pattern of consumers’ taste heterogeneity under which the first‐best world social optimum arises as a noncooperative Nash equilibrium. Consumers’ tastes are characterized by the strength of their preference for home and foreign goods. Nash implementation of the first‐best obtains when in every tax jurisdiction the number of consumers who display a home bias (those consumers who prefer purchasing the home good to shopping abroad at equal prices) equals, for every magnitude of the home bias, the number of consumers who display an “import bias” (those who instead prefer shopping abroad) equal in magnitude.

This article provides an original framework for analyzing networks of scientific collaborations in Europe at regional level. Which are the determinants of the observed clustering phenomenon? Which is the role of the territories? The aim of this article is to provide empirical evidence in order to answer to these questions. For this, we base our analysis on scientific collaborations between European regions in eight different disciplines (e.g. Medicine, Chemistry…) over the period 2001-2011. A normalized centrality measurement is proposed. We test the impact of territorial resources and field scientific characteristics on regions centrality in each of the analyzed discipline. Firstly, the analysis highlights a strong heterogeneity between disciplines, showing the need of carrying out specific investigation for each of them. Second, the results show the different roles played by local resources, according to the disciplines. Finally, the article discusses the implications of these results in terms of science and innovation policies.

The present paper models the relationship between a research unit wishing to launch a new project and a biobank capable of supplying the necessary biological resources (biological samples and associated data). Although the project’s aim may be to produce an innovative product or process, such as a new drug or treatment protocol, whether it will be a success is uncertain. Neither the biobank nor the research unit can know a project’s commercial value in advance, but this value is endogenous, that is, it depends on the actions and decisions of the actors involved. Our objective was to ascertain how these actions and decisions affect the project’s value.

There is solid scientific evidence predicting that a large part of the developing world will suffer a greater incidence of extreme weather events, which may increase displacement migration. We draw on the new economics of migration to model migration decisions of smallholder and rain-dependent farm households in rural Ethiopia and investigate both the ex-ante and ex-post impacts of climate variables. Using detailed household survey panel data matched with rainfall data, we show that weather variability – measured by the coefficient of variation of rainfall – has a strong positive impact on the probability of sending a migrant. This implies that households engage in migration to cope with risk ex-ante. We also find evidence suggesting that rainfall shocks have ex-post impact on households’ likelihood of migration, but the effect is not significant at the conventional levels. Instrumental variables probit regression results also show that controlling for endogeneity of income using a credible instrument is important to identify its impact on the decision to migrate. Our findings have important implications for policies aiming to improve the capacity of vulnerable households to adapt to climate change.

To address the issue of potential information asymmetries inherent in the estimation of deforestation baselines required by the current Reducing Emissions from Deforestation and Forest Degradation+ (REDD+) scheme, we offer a theoretical analysis of an extended scheme relying on the theory of incentives. We compare two types of contracts: a deforestation-based contract and a policy-based contract. Each of them implies a dramatically different information rent/efficiency trade-off due to domestic implementation and transaction costs. If the contract is deforestation-based (resp. policy-based), information rents are awarded to countries with the ex ante lowest (resp. highest) intended deforestation. We show that a general contract can be offered to recipient countries in which the type of instrument proposed is endogenous, independent of the historical trend, unlike the current REDD+ mechanism. Dividing countries into two groups corresponding to the deforestation-based instrument and the policy-based instrument helps the donor country to obtain efficient deforestation and avoided deforestation levels.

This paper investigates the impact on fiscal revenues of taxing a two-sided monopolistic platform offering personalized services to users and targeted advertising to sellers, based on the collection of users’ personal data. We show that the introduction of a small tax on data collection, which has been proposed in the French context by Collin and Colin, fails to increase fiscal revenues if the value-added tax (VAT) rate is high enough, due to a tax base interdependence effect between the two taxes. Under a supermodularity condition on the platform’s profit function as a function of its prices, this result generalizes to any per-unit tax. However, in some cases, an ad valorem tax on subscriptions or on advertising may raise fiscal revenues, irrespective of the VAT rate, as well as welfare.

This article analyzes the impacts of Environmental Tax Reform (ETR) when the government is constrained not to increase the public debt-to-output ratio. We consider an overlapping generations model with pollution. Public spending for pollution abatement are financed by tax revenues and public debt. We show that keeping constant the public debt-output ratio is not an obstacle to attain a double dividend, i.e. an increase of both (i) environmental quality and (ii) aggregate consumption. First, if the capital stock is low and the pollution abatement is large enough, a successful ETR consists in a rise of the environmental tax, compensated by a decrease of the income tax. Secondly, we show that the environmental tax revenues may help reduce the public debt-output ratio. We give conditions (on the initial level of the environmental tax and the debt-output ratio) such that an increase of the environmental tax, budget-balanced by a decrease of the debt-output ratio may also achieve a double dividend. We conclude that public debt crisis should not compromise ETR, instead, environmental tax revenues could be part of the solution. JEL: Q5, H23, H63 / KEY WORDS: Environmental Tax Reform, Debt, Public Emission Abatement, Double Dividend, Overlapping Generations Model

In many cases, consumers cannot observe a single firm’s investment in environmental quality or safety, but only the average quality of the industry. The outcome of the investment is stochastic, since firms cannot control perfectly the technology or external factors that may affect production. In addition, firms do not know consumers’ valuation of quality. We characterize the solution of the firms’ investment game and show that the value of stopping investments when firms are already investing in quality can be negative when the free-riding incentives dominate. The existence of systematic uncertainty on the outcome of investment slows down investment in quality, compared to a situation without uncertainty. The uncertainty on consumers’ willingness to pay for quality can speed up or slow down investment. We also obtain the counterintuitive result that information acquisition may decrease the overall level of quality.

This paper provides a systematic cross-country investigation of the relation between a firm’s growth volatility and its size. For the first time the analysis is carried out using comparable and representative sets of data sourced by official business registers of an important number of countries. We show that there exists a robust negative relation between growth volatility and size with an average elasticity equal to . We check the robustness of this result against a number of potential sources of bias and in particular with respect to sectoral disaggregation and against the inclusion of firm age. Our result is consistent with the idea that independently from specific country characteristics there exists a common underlying mechanism driving the elasticity between size and growth volatility. We then propose two mechanisms able to explain our result and we conclude discussing its relevance with respect to the recent literature on granularity.

Corporate social responsibility has gone mainstream, and many companies have taken meaningful steps towards a more sustainable future. Yet global environmental indicators continue to worsen, and individual corporate efforts may be hitting the point of diminishing returns. Voluntary action by the private sector is not a panacea-regulatory action by the public sector remains necessary. Such public sector progress will be more likely if it is supported by influential segments of the business community. Recent court rulings in the U.S. make it easy for companies to hide their political activities from the public, yet the indicators of CSR used by ratings agencies and socially responsible investment funds mostly ignore corporate political action. We argue that it is time for CSR metrics to be expanded to critically assess and evaluate firms based on the sustainability impacts of their public policy positions. To enable such assessments, firms need to become as transparent about their political activity as many have become about their CSR efforts, and CSR rating services and ethical investment funds need to demand such information from firms and include an assessment of corporate political activity in their ratings. † We thank the Albert and Elaine Borchard Foundation for their generous financial support.

This article examines the recent literature on macroeconomics and the environment from the perspective of the methodological approach, the questions asked and the types of responses given. It also reviews the place of the environment in textbooks and major macroeconomics journals. It shows that almost no space is given to environmental issues in short-term macroeconomics. Environmental issues are perceived as affecting the long-term and the structure of economies rather than the current situation. It can therefore be expected that studies on growth and the teaching of theories of growth would give them an important role. The article shows that while this is partly the case with regard to the literature, it does not hold at all with regard to teaching. The road ahead for truly integrating environmental issues into macroeconomics remains long.

Nous présentons une méthodologie permettant d’estimer les déterminants de la formation de réseaux de diffusion technologique à partir des modèles d’adoption des technologies. Nous appliquons cette méthodologie à l’énergie éolienne, qui est l’une des technologies clés pour l’atténuation du changement climatique. Nos résultats soulignent que, en particulier, les relations à long terme, mesurées par l’intégration économique, sont des déterminants clés de la diffusion technologique. Les mesures de soutien spécifiques sont moins pertinentes, du moins pour expliquer la marge extensive de la diffusion. Nos résultats soulignent également que la portée de la diffusion technologique est beaucoup plus large que ce que suggère la prise en compte des seuls projets MDP, qui sont particulièrement concentrés sur la Chine et l’Inde. Enfin, le réseau de diffusion technologique déduit de notre approche met en évidence le rôle central des pays européens dans le processus de diffusion et l’absence de grands hubs parmi les pays en développement.

The paper provides an original empirical approach to investigate multi-product firms’ export patterns across destinations by considering the whole mix of products exported by a firm, formally defined as a product-vector. The proposed methodology allows to take into account a firm’s choice of both exporting and non-exporting a product to a destination and to consider different forms of product complementarity that can generate product combinations. The empirical analysis uses a panel of transactions level data for the universe of Italian and French firms and complements the existing evidence along a few dimensions. First, we show that there is a high level of sparsity: selection of products at destination is indeed very severe. Second, we document that firms export several different combinations of product vectors across markets. Relatedly a high level of diversity is detected also when considering the intensive margin, pointing to a substantial departure from a stable global product hierarchy. Finally, we provide evidence that at the same time there exists a stable component in firms’ product vectors across destinations composed by products which are not necessarily the most important in terms of sales, suggesting rich form of complementarities across goods. Products belonging to this stable component are less likely to be discarded as a consequence of an exogenous shock such as the dismantling of the MFA quotas after accession of China to the WTO.

We match climate data to migration data from the 1991 and 2001 Indian Censuses to investigate the impact of climate variability on internal migration. The article makes four contributions to the existing literature on macro-level migration flows. First, use of census data allows us to test and compare the effect on migration of climatic factors prior to migration. Second, we introduce relevant meteorological indicators of climate variability, to measure the frequency, duration, and magnitude of drought and excess precipitation based on the Standardized Precipitation Index. Third, we estimate the total effect (direct and indirect effects) of climate variability on bilateral migration rates. Fourth, we examine three possible channels through which climate variability might induce migration: average income, agriculture, and urbanization. The estimation results show that drought frequency in the origin state increases inter-state migration in India. This effect is stronger in agricultural states, and in such states the magnitude of drought also increases inter-state migration significantly. Drought frequency has the strongest effect on rural–rural inter-state migration.

This article offers a theoretical analysis of the impact that the introduction of aquaculture has on wild fish stocks and consumer utility, taking into account three key components: (1) the dependence of aquaculture on reduction fisheries for the feeding of the farmed species; (2) biological interactions between the wild edible species—the predator—and the wild feed species—the prey; and (3) consumer preferences for wild and farmed fish. Fisheries are in open access, while the aquaculture sector is competitive. We show that when biological interactions are moderate, the introduction of aquaculture is beneficial in the long run: it improves consumer utility and alleviates the pressure on the edible fish stock. Results are deeply modified when biological interactions are strong: the stock of edible wild fish is reduced and the introduction of aquaculture may even cause a decrease in consumer utility. We then explore the consequences of improving aquaculture efficiency and the sensitivity of consumer preferences to the farmed fish characteristics, in the case where biological interactions are absent. Lastly, we analyze how our outcomes on the entry of aquaculture are affected when the wild edible fishery is optimally regulated, in combination with different assumptions on the regulation of the feed fishery. Results are again conditional on the intensity of biological interactions.

To limit greenhouse-gas emissions, is it necessary to restrict international trade? By dissociating where products are produced from where they are consumed, international trade contributes significantly to greenhousegas emissions worldwide, especially when goods are transported. It also displaces the location of emissions: the consumption-induced carbon footprint of OECD countries is higher than their level of emissions. Large emerging countries find themselves in the opposite case. However, halting international trade would be particularly ineffective to reduce GHG emissions. According to oursimulations, raising average import tariffs to 17% (as opposed to current 5%, except for agricultural products) and accepting a fall in aggregate production of 1.8% would only lead to 3.5% GHG emission reduction by 2030. We confirm that a uniform and moderate import tariff imposed by a “club” of countries adopting ambitious and binding policies to fight climate change, against all imports from countries outside of the club, would be effective.

We consider contracts for public transport services between a public authority and a transport operator. We build a structural endogenous switching model where the contract choice results from the combined effects of the incentivization scheme aimed at monitoring the operator’s efficiency and the political agenda followed by the regulator to account for the voice of private interests. Our results support theoretical predictions as they suggest that cost-plus contracts entail a higher cost for society than fixed-price contracts but allow the public authority to leave a rent to a subset of individuals. Accounting for transfers to interest groups in welfare computations reduces the welfare gap between cost-plus and fixed-price regimes.

A government designs anonymous income transfers between a continuum of citizens whose income valuation is privately known. When transfers are deterministic, the incentive constraints imply equal treatment independently of the government’s taste for redistribution. We study whether random transfers may locally improve upon the egalitarian outcome. A suitable Taylor expansion offers an approximation of the utility function by a quasilinear function. The methodology developed by Myerson to deal with incentive constraints then yields a necessary and sufficient condition for the existence of a socially useful randomization. When this condition is met a large set of lotteries are locally improving. A special menu made of two lotteries only is of interest: all the agents with low risk aversion receive the same random transfer, financed by a deterministic tax paid by the high risk aversion agents.

A government agency delegates to a provider (hospital, medical gatekeeper, school, social worker) the decision to supply a service or treatment to individual recipients. The agency does not perfectly know the distribution of individual treatment costs in the population. The single-crossing property is not satisfied when the uncertainty pertains to the dispersion of the distribution. We find that the provision of service should be distorted upwards when the first-best efficient number of recipients is sufficiently high.

This paper addresses the issue of favoritism at the design stage of complex procurement auctions. A local community of citizens wants to procure a complex good or project and lacks the ability to translate its preferences into operational technical specifications. This task is delegated to a public officer who may collude with one of the firms at the design stage of the procurement auction in exchange of a bribe. Assuming that it is prohibitively costly to provide a justification for many aspects, we investigate two simple accountability mechanisms that ask the public officer to justify one aspect of the project, with the threat of being punished if he fails: a random challenge mechanism and an alert-based mechanism that requires justifying one aspect on which the rivals of the winning contractor send a red ag. Relying on losing contractors enables the community to deter favoritism significantly more easily than the random challenge procedure as it allows to use information that is shared by potential contractors in the industry. The level of penalty needed to fully deter corruption is lower, independent of the complexity of the project and depends on the degree of differentiation within the industry. Below this threshold, favoritism occurs in some states of nature and we characterize and compare the different equilibrium patterns of corruption under both mechanisms. A more elaborate example suggests that the alert-based mechanism tends to lead to more standard specifications of projects.

This paper investigates the distributional and efficiency consequences of an environmental tax reform, when the revenue from the green tax is recycled by varying labor tax rates. We build a general equilibrium model with imperfect heterogeneous labor markets, pollution consumption externalities, and non-homothetic preferences (Stone-Geary utility). We show that in the case where the reform appears to be regressive, the gains from the double dividend can be made Pareto improving by using a redistributive non-linear income tax if redistribution is initially not too large. Moreover, the increase of progressivity acts on unemployment and can moderate the trade-off between equity and efficiency. We finally provide numerical illustrations for three European countries featuring different labor market behaviors. We show that a double dividend may be obtained without worsening the initial inequalities if the green tax revenues are redistributed with a progressivity index lower for France than for Germany and UK.

We use the Targeted Subsidies Reform implemented in Iran in 2011 to recover empirically the social valuations of Iranian households relying on the assumption of optimal taxes. Unlike the existing literature, we do not restrict attention to a specific pattern for the incentive constraints associated with nonlinear income taxation. Instead we recover the Lagrange multipliers corresponding to these constraints. We find evidence of a significant redistribution toward the bottom three deciles of the income distribution before the reform. This redistribution is however limited by an incentive constraint where the rich envy the social treatment of the poor. At the outcome of the reform incentives no longer matter and the social welfare function of the government of Iran displays a Benthamite-like form.

The Framework programmes created by the European Union are the main financial tools used to support cooperative R&D activities in the EU. Unlike previous empirical studies, this paper suggests that their impact on firms’ competitiveness is significant. We analyze industry-oriented research joint ventures supported by the Fifth European Framework Programme between 1998 and 2002. A key feature of this Programme is that funding is available to the firms based on social and economic concerns instead of pure performance criteria, which guarantees that financial support is not granted conditional on technological opportunities. This allows us to identify the causal effect of the programme on firms’ performance using the funding available to the firms in their respective industries as a source of exogenous variation in the decision to participate in the programme. Our results suggest that participation in research projects may raise labor productivity by at least 44.4% while it has very limited effect on profit margin.

This paper investigates empirically the determinants of the CO2 emissions from the residential and commercial sectors in France. We use panel data on the 22 French administrative regions over the 1995-2009 period. We estimate the relationship between regional CO2 emissions per capita, regional GDP, temperature, the annual number of frost days, heating technology and energy prices. We use these results to assess the regional consequences of implementing a carbon tax of 22€ per metric ton of CO2, and conclude that this policy would increase inequalities between regions. We show that a region-specific carbon tax that equalizes the tax burden among regions, instead of a homogenous national tax, may compensate these inequalities and reduce total CO2 emissions. Last, we show that taking regional specific effects into account in the design of the environmental tax reform may help make this policy more acceptable.

Lancé en 2010, le Programme d’investissements d’avenir (PIA) a pour ambition de stimuler les activités de recherche, de développement et d’innovation dans des secteurs ciblés et porteurs de croissance, aussi divers et variés que l’enseignement supérieur et la recherche, l’économie numérique, la santé ou encore le développement durable. Près de 50 milliards d’euros de crédits ont été engagés pour les deux premiers volets des PIA qui ont été reconduits pour la troisième fois en juin 2016 et dotés de 10 milliards d’euros supplémentaires. Le PIA est ainsi devenu un instrument majeur de la politique de soutien à l’innovation en France, aux côtés du crédit d’impôt recherche (CIR).Comme pour toute politique d’aide publique en faveur des entreprises, se pose la question de l’incidence de ces aides sur les comportements des entreprises ainsi que sur leurs performances. En effet, afin de juger de la pertinence et de l’efficacité d’une telle politique de soutien aux entreprises, il est crucial de déterminer i) si ces aides viennent s’ajouter aux dépenses en R&D des entreprises tout en les incitant à investir davantage ou si au contraire elles viennent s’y substituer ; et ii) si ces aides permettent d’améliorer les performances des entreprises bénéficiaires et dans quelle mesure elles affectent les performances des entreprises non bénéficiaires. En se concentrant sur le PIA géré par l’Agence de l’environnement et de la maîtrise de l’énergie (ADEME), spécialisée dans les thématiques environnementales comme celles de la transition énergétique ou de la croissance « verte », l’objectif de la présente étude est d’évaluer ex post les effets des aides octroyées par l’ADEME sur les entreprises bénéficiaires.

Consider a simple general equilibrium economy with one representative consumer, a single competitive firm and the government. Suppose that the government has to finance public expenditures using linear consumption taxes and/or a lump-sum tax on profits redistributed to the consumer. This note shows that, if the tax rate on profits cannot exceed 100 percent, one cannot improve upon the second-best optimum of an economy with constant returns to scale by using a less efficient profit-generating decreasing returns to scale technology.

Science policy is increasingly shifting towards an emphasis in societal problems or grand challenges. As a result, new evaluative tools are needed to help assess not only the knowledge production side of research programmes or organisations, but also the articulation of research agendas with societal needs. In this paper, we present an exploratory investigation of science supply and societal needs on the grand challenge of obesity – an emerging health problem with enormous social costs. We illustrate a potential approach that uses topic modelling to explore: (a) how scientific publications can be used to describe existing priorities in science production; (b) how policy records (in this case here questions posed in the European parliament) can be used as an instance of mapping discourse of social needs; (c) how the comparison between the two may show (mis)alignments between societal concerns and scientific outputs. While this is a technical exercise, we propose that this type of mapping methods can be useful to domain experts for informing strategic planning and evaluation in funding agencies

L’objectif de ce papier, reprenant ma conférence présidentielle au congrès de l’AFSE 2016, est double. Il est d’abord de convaincre les lecteurs que la transition énergétique, entre un présent où nous brulons massivement les énergies fossiles intensives en carbone sources du changement climatique et un futur où nous serions capable de produire une énergie totalement décarbonée, est inévitable et ne peut attendre. Il est d’autre part d’examiner si l’utilisation de gaz de schiste comme combustible transitionnel permettant de sortir du charbon tout en gagnant du temps pour mettre au point les innovations technologiques indispensables au déploiement des énergies renouvelables est ou non une bonne idée.

La fiscalité incitative cherche à modifier les comportements des agents en utilisant l’instrument de l’impôt pour encourager des comportements jugés comme bons tels la recherche, l’innovation ou certains investissements et pour dissuader d’autres, jugés néfastes. Du point de vue économique, sa justification est avant tout la maximisation du bien-être social, lorsque, en présence d’externalités négatives, le régulateur pousse à leur internalisation via un signal-prix. Nous montrons ici dans le cas de l’écofiscalité les multiples facettes de cet instrument fiscal – ses effets distributifs ainsi que ceux sur la compétitivité, la différence de nature entre fiscalité incitative et fiscalité de rendement – et nous dressons le cadre pour qu’une réforme fiscale environnementale neutre budgétairement puisse déboucher sur une situation de double dividende.

International di¤erences in fuel taxation are huge, and may be justi…ed by different local negative externalities that taxes must correct, as well as by di¤erent preferences for public spending. In this context, should a worldwide uniform carbon tax be added to these local taxes to correct the global warming externality? We address this question in a second best framework à la Ramsey, where public goods have to be …nanced through distortionary taxation and the cost of public funds has to be weighted against the utility of public goods. We show that when lump-sum transfers between countries are allowed for, the second best tax on the polluting good may be decomposed into three parts: one, country-speci…c, dealing with the local negative externality, a second one, country-speci…c, dealing with the cost of levying public funds, and a third one, global, dealing with the global externality and which can be interpreted as the carbon price. Our main contribution is to show that the uniformity of the carbon price should still hold in this second best framework. Nevertheless, if lump-sum transfers between governments are impossible to implement, international di¤erentiation of the carbon price is the only way to take care of equity concerns. keywords: carbon price, second best, Pigovian taxation

This paper analyzes the joint design of fiscal and cap-and-trade instruments in climate policies under uncertainty. Whether the optimal mechanism is a mixed policy (with some firms subject to a tax and others to a cap-and-trade) or a uniform one (with all firms subject to the same instrument) depends on parameters reecting preferences, production, and, most importantly, the stochastic structure of the shocks affecting the economy. This framework is then used to address the issue of the non-cooperative design of climate regulation systems in various areas worldwide under uncertainty. We characterize the resulting ineficiency, we show how the Pareto argument in favor of merging ETS of different regions is reinforced under uncertainty, and we discuss the non-cooperative design of mixed systems.

Exploiting data on the product-destination-level transactions of a large panel of Italian firms, we provide evidence that financial constraints affect price variation across exporters. Constrained exporters charge higher prices than do unconstrained firms that export to the same product-destination market. This pattern is the result of a two-fold effect. Distressed firms pass on their higher production costs through prices. However, they also charge higher mark-ups. We explain this evidence referring to models in which rival firms produce different brands of the same product for customers with significant switching costs and producers face capital market imperfections when they need external financing. Our empirical investigations corroborate this explanation: price gaps are higher when switching costs or other forms of demand rigidity are expected to be more relevant.

We propose merger guidelines for bidding markets through the construction of a simple test. It is applied in the particular context of the French urban transport industry. It designs the optimal auction and captures two opposite forces at stake: on the one hand, the optimal auction is biased against a merger due to a loss of competition; on the other hand, potential efficiency gains bias the optimal allocation towards the merger firm. The two effects can be nested in a single equation condition which determines whether the merger improves the consumer net surplus. We suggest that the merger between Transdev and Veolia is consumer surplus improving if the efficiency gains from the merger allow both firms to decrease their initial costs inability by at least 17.9% and 17.8% respectively.

AVANT-PROPOS: Comprendre la complexité du monde vivant est l’une des grandes préoccupations des scientifiques, alors même que la prise de conscience collective de sa fragilité s’opère à la fin des années 1980, période à laquelle apparaît le mot « biodiversité » (1992). L’écologie a permis de mettre en évidence les diversités de ce patrimoine naturel reconnu vital pour les sociétés humaines, dont les activités le menacent de plus en plus. Les organismes vivants, dans leur diversité, s’adaptent et évoluent en réponse aux variations à court terme et aux changements à long terme de leurs environnements. Le croisement d’informations d’origines multiples, comme les archives naturelles et historiques portant sur des milieux diversement anthropisés ou encore la modélisation, conduit à estimer que la biosphère est aujourd’hui confrontée à des changements importants et rapides, dont le déterminisme est avant tout anthropique. Si la vitesse et l’ampleur des processus et leurs mécanismes restent à définir, de nombreux signes témoignent d’une sixième crise majeure de la biodiversité : extinctions d’espèces, changements d’aires de distribution, invasions, évolution d’agents pathogènes, dégradation de la qualité des ressources et des paysages. La lutte contre l’érosion de la biodiversité, dont les services sont indispensables à la survie des sociétés humaines, constitue l’un des enjeux écologiques et socio-économiques majeurs pour les années à venir. Le CNRS (Mission pour l’interdisciplinarité (MI), Institut écologie et environnement (INEE), Institut des sciences humaines et sociales (INSHS), Institut des sciences de l’univers (INSU)) a lancé en 2012 un appel à projets commun dans le domaine du droit et de l’économie de l’environnement et de la biodiversité, favorisant une approche globale et transversale pour répondre à la complexité de ces enjeux. Il s’agit des Projets exploratoires premier soutien (PEPS) qui visent à faire émerger de nouveaux questionnements, fruits d’une réflexion interdisciplinaire, pour répondre aux défis liés à la perte de la biodiversité. Cette première étape a mis en évidence le besoin de poursuivre et d’approfondir une réflexion collective et interdisciplinaire associant des écologues, des économistes et des juristes pour répondre à l’un des défis actuels qui consiste à évaluer la biodiversité et ses fonctions comme ressource et services, à analyser ses capacités de résiliences ou encore s’interroger sur les questions de justice environnementale. Compte tenu des enjeux écologiques et socio-économiques liés à la dégradation de la biodiversité, le CNRS a organisé un colloque de prospective sur l’économie et le droit de la biodiversité en mobilisant ses équipes et leurs compétences scientifiques. Un collectif d’une quarantaine de chercheurs s’est réuni du 2 au 5 avril 2013 à Oléron.

The article examines the causal effect of financial constraints on firms’ exports. We exploit a firm-level proxy of constraints based on credit ratings and available for a large panel of Italian exporting and non-exporting firms. Our estimation strategy allows to cure for self-selection into exports and endogeneity of financial constraints. At the same time, we can control for unobserved firm fixed effects both in the selection and in the export equation, thus identifying the effect on exports of within-firm changes in financial constraints status. We find that financial constraints produce a sizable reduction in the value of a firm’s foreign sales.

This article analyzes the long-term consequences of nuclear waste storage within a general equilibrium framework. The objective is to determine the conditions for which the storage of waste, and thus the transfer of externalities towards the future, can be optimal. These conditions could explain the implementation of intergenerational externalities, justifying an intertemporal Not In My Back Yard behaviour. We first show that the choice of the policy instruments determines the feasibility of the storage policy. Indeed, economic stability imposes precise levels of the rate of storage or of the tax rate, making it possible to avoid chaotic economic dynamics. Under these specific conditions, and depending on the period at which an accident may occur and on the value of the social discount rate, we show that storing all the nuclear waste may be optimal.

Actuellement, la fiscalité environnementale française répond moins à une finalité écologique qu’à un objectif plus traditionnel de fiscalité de rendement. Les signes manifestes de cette inadéquation sont la très grande part prise par la fiscalité de l’énergie et le faible niveau de la plupart des taux de taxe, qui souvent ne frappent qu’implicitement les produits polluants. Réformer la fiscalité française supposerait de la « verdir » dans son ensemble en appliquant des taux de taxes en relation avec les dommages marginaux. La réussite de la réforme et son acceptation par les contribuables sont conditionnées par le mécanisme de redistribution associé, les efforts de pédagogie et d’information, la transparence mais aussi, paradoxalement, par l’audace des mesures prises.

The aim of this paper is to investigate the main factors that have contributed to the decline in aggregate energy intensity of the Tunisian economy, during the period 1980–2007. Using the Logarithmic Mean Division Index (LMDI) decomposition method, we decompose the total changes in energy intensity into inter-fuel substitution effects, technological effects, and structural effects. The decomposition analysis is carried out at two levels of sectoral disaggregation (3 sectors and 13 sub-sectors) and uses three energy sources: petroleum, natural gas, and electricity. Our results show that the main contributor to the decline in energy intensity of the Tunisian economy throughout the period studied is the technological effect. This result was confirmed when we decomposed the energy intensity changes in the industrial and service sectors. On the other hand, the inter-fuel substitution effect contributed to increasing energy intensity, but without affecting its general downward trend. Finally, for the structural effects, we observed a significant mutual effect of cancellation at sector and sub-sector levels.

This paper studies rationalizability in a linear asymmetric Cournot oligopoly with a unique Nash equilibrium. It shows that mergers favors uniqueness of the rationalizable outcome. When one requires uniqueness of the rationalizable outcome maximization of consumers’ surplus may involve a symmetric oligopoly with few firms. We interpret uniqueness of the rationalizable outcome as favoring a dampening of strategic ‘coordination’ uncertainty. An illustration to the merger between Delta Air Lines and Northwest shows that a reallocation of 1 % of market share from a small carrier to a larger one has implied a lower production volatility over time, yielding a 1.5 % decrease in the coefficient of variation of number of passengers.

The concept of environmental migrants occurs frequently in the policy debate, in particular with regard to climate change and the incidence of such migration in low-income countries. This article reviews the economic studies of environmentally induced migration. It includes recent empirical analyses that try to link environmental change to migration flows and the spatial distribution of population. A consensus seems to emerge that there is little likelihood of large increases in international migration flows due to climate variability. The evidence to date shows that regional migration will be affected, however, either on the African continent or internally, within country borders. Theoretically, environmentally induced migration can be analyzed using different frameworks: the classical Harris-Todaro model of rural-urban migration, new economic geography models, models grounded in environmental economics of pollution externalities with free factor mobility, and the new economics of labor migration. I review some of the latest attempts to analyze environmentally induced migration theoretically and the policy-relevant conclusions that can be drawn.

We study an overlapping generations model composed of two productive sectors: the first produces a virgin good and the second recycles a good from a previous period. When the profit of the recycling sector is in its increasing region, endogenous fluctuations emerge through a flip bifurcation when leisure and consumption are complementary. Conversely, when profit is in its decreasing region, deterministic cycles emerge also under the gross substitutability assumption. The steady state becomes indeterminate through a flip or a Hopf bifurcation, provided leisure and consumption are complements. We also study the social optimum and the altruistic market economy.

The paper identifies a necessary and sufficient condition for a deterministic local optimum to be locally improved upon by a stochastic deviation. When this condition is satisfied, a method to construct the stochastic allocations that increase the objective is provided. This technique is applied to a number of adverse selection and moral hazard problems.

In a dynamic model with overlapping generations of consumers, we study duopolistic competition when firms can price discriminate, at each period, between their previous customers and the consumers that they have never served. Long-term contracts are not enforceable. In (Markov-perfect) equilibrium, one firm charges higher prices to its past customers than to its new customers, as past customers have revealed their strong preferences for the firm; the other firm, however, rewards its previous customers by charging lower prices to them than to its new customers. This loyalty reward strategy comes from the interplay between the firms’ usual incentive to extract surplus from consumers with revealed strong preferences and their incentives to acquire information and to recognize their young loyal customers. The result also relies on the firms’ inability a priori to tell different generations apart. It is the outcome of the unique equilibrium of a simplified two-period (or T-period) version of the game and holds with forward-looking consumers who are impatient enough.

European countries have increased their use of environmental tax instruments by designing new tax bases. But many countries face opposition from public opinion, for fear of the distributive consequences of these environmental tax reforms. This paper sheds light on the distributive consequences of environmental tax policies when households are heterogeneous. The objective is to assess whether an environmental tax reform could be Pareto improving, when the revenue of the pollution tax is recycled by a change in labor tax properties. We show that, whatever the degree of regressivity of the environmental tax alone, it is possible to design a recycling mechanism that renders the tax reform more Pareto efficient, by simultaneously decreasing the wage tax and increasing its progressivity.

We build, calibrate and simulate a stylized energy-economy model designed to evaluate the magnitude of carbon tax that would allow the French economy to reduce by a factor of four its CO2 emissions at a forty-year horizon. We estimate the substitution possibilities between fossil energy and other factors for households and firms. We build two versions of the model, the first with exogenous technical progress, and the second with an endogenization of the direction of technical progress. We show that if the energy-saving technical progress rate remains at its recent historical value, the magnitude of the carbon tax is quite unrealistic. When the direction of technical progress responds endogenously to economic incentives, CO2 emissions can be reduced by more than that allowed by the substitution possibilities, but not by a factor of four. To achieve this, an additional instrument is needed, namely a subsidy to fossil energy-saving research. The redirection of technical progress, which is a driver of energy transition, comes at a small cost in terms of the overall growth rate of the economy. [ABSTRACT FROM AUTHOR]

Combining detailed data on export transactions and an informative firm-level measure of financing constraints, this article provides new evidence on the extent and dynamics of product and geographical diversification of constrained exporters. Financial constraints associate with: (i) narrower product/destination margins, (ii) higher probability to drop products and destinations, (iii) larger loss of export value associated to dropping product or destination markets, (iv) higher probability to discard products with relatively large share in firm total export values, and (v) larger likelihood to drop country markets that are bigger, richer, geographically closer and with a relatively larger share in total firm export value.

This article analyzes the consequences on capital accumulation and environmental quality of environmental policies financed by public debt. A public sector of pollution abatement is financed by a tax and/or public debt. We show that if the initial capital stock is high enough, the economy monotonically converges to a long-run steady state. On the contrary, when the initial capital stock is low, the economy is relegated to an environmental-poverty trap. We also explore the implications of public policies on the trap and on the long-run stable steady state. In particular, we find that government should decrease debt and increase pollution abatement to promote capital accumulation and environmental quality at the stable long-run steady state.

Competition and the State analyzes the role of the state across a number of dimensions as it relates to competition law and policy across a number of dimensions. This book re-conceptualizes the interaction between competition law and government activities in light of the profound transformation of the conception of state action in recent years by looking to the challenges of privatization, new public management, and public-private partnerships. It then asks whether there is a substantive legal framework that might be put in place to address competition issues as they relate to the role of the state. Various chapters also provide case studies of national experiences. The volume also examines one of the most highly controversial policy issues within the competition and regulatory sphere—the role of competition law and policy in the financial sector. This book, the third in the Global Competition Law and Economics series, provides a number of viewpoints of what competition law and policy mean both in theory and practice in a development context.

This study analyzes the effect of financial constraints (FCs) on firm dynamics. We measure FCs with an official credit rating, which captures availability and cost of external resources. We find that FCs undermine average firm growth, induce anti-correlation in growth patterns, and reduce the dependence of growth volatility on size. FCs are also associated with higher volatility and asymmetries in growth shock distributions, preventing young fast-growing firms especially from seizing attractive growth opportunities and further deteriorating the growth prospects of already slow-growing firms, particularly if old. The sub-diffusive nature of the growth process of constrained firms is compatible with the distinctive properties of their size distribution.

Comment expliquer les difficultés de la fiscalité écologique en France ? Nous rappelons les fondements, la logique et la nécessité d’une telle fiscalité. Depuis le début des années 2000, les deux dernières tentatives françaises de renforcement de la fiscalité environnementale se sont notamment heurtées à des inquiétudes concernant les répercussions sur le pouvoir d’achat des ménages et la compétitivité des entreprises concernées. Si le cadre européen ne semble pas encore propice au développement de la fiscalité écologique, nous préconisons un approfondissement de la progressivité de la fiscalité existante et son remplacement partiel par la fiscalité écologique.

We study how asymmetric information affects the set of rationalizable solutions in a linear setup where the outcome is determined by forecasts about this same outcome. The unique rational expectations equilibrium is also the unique rationalizable solution when the sensitivity of the outcome to agents’ forecasts is less than one, provided that this sensitivity is common knowledge. Relaxing this common knowledge assumption, multiple rationalizable solutions arise when the proportion of agents who know the sensitivity is large, and the uninformed agents believe it is possible that the sensitivity is greater than one. Instability is equivalent to existence of some kind of sunspot equilibria.

This note characterizes the optimal base for commodity taxation in the presence of administrative fixed costs varying across goods. For low tax rates, the optimal base only comprises commodities whose discouragement index is greater than the ratio of their administrative costs to the tax they yield. An illustration with UK data shows that a category of goods should be taxed only if the revenue generated on this category is at least ten times greater than its administrative fixed cost. The cost imputable to the category of goods taxed at the standard rate would be at most 6 percent of total VAT revenue.The administration cost associated with categories of goods currently tax free could justify exemption.

This chapter looks at the impact of instruments directly targeting consumers’ choices concerning food consumption, such as organic labelling and raising awareness through public information campaigns. It provides a better understanding of the main determinants for consuming organic food and products that take animal welfare into account, and examines how much more households are willing to pay for these products.

La théorie économique affirme que la renégociation des contrats empêche d’atteindre une solution efficace qui peut être obtenue en cas d’engagement complet du régulateur. L’évaluation du coût de la renégociation par rapport au scénario ” engagement complet ” reste une question ouverte d’un point de vue empirique. Pour répondre à cette question, nous ajustons un modèle structurel principal-agent avec renégociation à un ensemble de contrats de services de transport urbain. Le modèle tient compte de deux caractéristiques importantes de l’industrie. Tout d’abord, seuls deux types de contrats sont utilisés dans la pratique (prix fixe ou coût du service). Ensuite, les subventions sont plus importantes lorsque un contrat de type coût du service a été signé avant un contrat à prix fixe. Nous comparons ensuite le scénario avec renégociation et celui plus hypothétique d’engagement total. Nous concluons que les gains de bien-être issus de l’amélioration de l’engagement seraient importants, mais reviendraient essentiellement aux opérateurs.

The Clean Development Mechanism (CDM) is one of three flexible mechanisms included in the Kyoto Protocol. It enables Annex I countries to finance emission reductions in developing (non-Annex I) countries and use the credits thus obtained to meet their emission reduction commitments under the Kyoto Protocol. The CDM has two objectives: to reduce the costs of compliance of the Annex I countries’ emission reduction commitments, and to assist developing countries in achieving sustainable development and in contributing to the ultimate objective of the United Nations Framework Convention for Climate Change (UNFCCC). The major part of emission reductions under the CDM (certified emission reductions – CERs) comes from renewable energy investments, reduction of nonCO2 greenhouse gases (hydrofluorocarbons, perfluorocarbons, and nitrous oxide), and energy-efficiency projects. Over two-third of projects and emission reductions occur in China and India. The uneven geographical distribution of projects and the lack of consistent control of projects’ contribution to sustainable development make some contend that the CDM has not fulfilled its initial objectives. On the other hand, it has brought forth a substantial amount of CERs, and it is the only Kyoto Mechanism to bring developing countries into the efforts of the UNFCCC, notably through unilateral projects developed solely by the developing host country.

Ce manuel présente les principaux modèles utilisés aujourd’hui pour décrire l’évolution de l’économie dans le moyen terme (fluctuations conjoncturelles) et le long terme (croissance). Les versions les plus simples du modèle à générations imbriquées et du modèle de croissance optimale sont progressivement enrichies pour éclairer des questions de politique économique actuelles. Le manuel étudie par exemple l’influence de notre système de retraite sur l’accumulation du capital et la croissance, les conséquences d’un financement des transferts sociaux par l’impôt ou par des cotisations assises sur les salaires, ou bien l’effet d’une plus grande liquidité sur l’instabilité de l’économie. Il discute aussi les principales hypothèses sur lesquelles reposent ces modèles, notamment celle de l’agent représentatif ou d’anticipations rationnelles. Chaque chapitre est suivi de nombreux exercices et de problèmes originaux qui permettront aux étudiants de niveau master d’assimiler son contenu.

This article analyzes the consequences of environmental tax policy under public debt stabilization constraint. A public sector of pollution abatement is financed by a tax on pollutant emissions and/or by public debt. At the same time, households can also invest in private pollution abatement activities. We show that the economy may be characterized by an environmental-poverty trap if debt is too large or public abatement is not sufficiently efficient with respect to the private one. However, there exists a level of public abatement and debt at which a stable steady state is optimal.

With the development of modern information technologies, relying on nanotechnologies and remote sensing, a number of systems can be envisaged that allow for monitoring of the negative externalities generated by producers, consumers or travelers – road pricing schemes or individual emission meters for automobiles are two examples. We analyze a dynamic model of stock pollution when the regulator has incomplete information on emissions generated by heterogeneous agents. Our contribution is to explicitly study a decentralized policy for adoption of monitoring equipment over time. We determine second-best tax rates, the pattern of monitoring technology adoption, and identify conditions for the voluntary diffusion of monitoring technologies over time. Simulations show the welfare gains compared to alternative policies.

Environmentally-induced migration can be analyzed through several theoretical frameworks: the new economics of labour migration, models grounded in environmental economics that analyze pollution externalities under the assumption of free factor mobility, international trade models as well as new economic geography models of the spatial distribution of population. This review surveys some of the latest attempts to analyze environmentally-induced migration, both empirically and theoretically, and aims at identifying the policy-relevant extensions that can be done. The topic is important given evidence on the current and future impact of climate change, and its incidence on low-income countries in particular. The review includes the recent empirical analyses that tries to link evidence on environmental change, in particular climate variability, to migration flows and the spatial distribution of population. A consensus seems to emerge that there is little likelihood of large increases in international migration flows due to climate variability. The evidence to date shows that regional migration will be affected, though, either on the African continent or internally, within country borders. The results have implications for urbanization trends and the sharing of common resources.

Cet article réexamine de façon théorique la question de l’unicité du prix du carbone au niveau international. Tous les pays doivent-ils payer le même taux de taxe carbone pour lutter contre le changement climatique ? L’argument qui permet de répondre par l’affirmative est un argument d’efficacité productive : l’unicité du prix induit l’égalisation des coûts marginaux de réduction des émissions entre tous les émetteurs, ce qui permet d’atteindre à moindre coût un objectif donné de réduction d’émissions. Parmi les arguments en sens contraire qui peuvent être avancés, nous nous intéressons à celui de l’existence préalable de taxes sur les énergies fossiles très différentes selon les pays. Nous montrons qu’en dépit de ces taxes préexistantes, destinées à corriger des pollutions locales et à financer des dépenses publiques, le prix du carbone doit être le même dans tous les pays à condition que des transferts forfaitaires entre pays soient possibles, pour prendre en compte les questions d’équité. Si ces transferts ne peuvent être mis en place, les prix du carbone doivent être différenciés.

This paper proposes a dynamic model of duopolistic competition under behaviorbased price discrimination with the following property: in equilibrium, a firm may reward its previous customers although long term contracts are not enforceable. A firm can offer a lower price to its previous customers than to its new customers as a strategic means to hamper its rival to gather precise information on the young generation of customers for subsequent profitable behavior-based pricing. The result holds both with myopic and forward-looking, impatient enough consumers.

The number of patent applications and “bad” patents issued has been rising rapidly in recent years. Based on this trend, we study the overload problem within the Patent Office and its consequences on the firms’ R&D incentives. We assume that the examination process of patent applications is imperfect, and that its quality is poorer under congestion. Depending on policy instruments such as submission fees and the toughness of the non-obviousness requirement, the system may result in a high-R&D equilibrium, in which firms self-select in their patent applications, or in an equilibrium with low R&D, opportunistic patent applications and the issuance of bad patents. Multiple equilibria often co-exist, which deeply undermines the effectiveness of policy instruments. We investigate the robustness of our conclusions as to how the value of patent protection is formalized, taking into consideration the introduction of a penalty system for rejected patent applications, as well as the role of commitment to a given patent protection policy.

We consider a model with two energy sources, a non-renewable one, cheap but polluting, and a renewable one, expensive but clean, let’s say coal and solar. The aim of environmental policy is to maintain atmospheric carbon concentration under a given ceiling, chosen to prevent an excessive rise of the temperature and catastrophic damages. Before the ceiling damages exist but remain small, hence manageable. We show first that costs matter a lot. Whatever abundant or rare, if solar is more expensive than coal at the ceiling, it will never be used before the end of the phase at the ceiling, when coal becomes so scarce that the ceiling will never be reached again. On the contrary, if solar is less expensive than coal at the ceiling, it may even be sufficiently cheap to be exploited before the ceiling, in which case first coal is exploited alone, next both resources are used together before, at and after the ceiling, and finally solar is exploited alone, after the exhaustion of coal. Second, the carbon shadow value is first increasing until the ceiling is reached, next decreasing during the phase at the ceiling, and finally is stabilized at a constant level after the ceiling. The initial carbon shadow cost is an increasing function of the value of the marginal damage, and a decreasing function of the ceiling. Lastly, contrary to intuition, higher marginal damages and/or a lower ceiling induce a delay in the penetration of solar and also a delay in the transition towards a totally clean energy.

Cet article vise à approfondir notre compréhension du fonctionnement de la concurrence dans l’industrie du transport urbain. Il donne un aperçu des contraintes concurrentielles qui sont à l’œuvre dans l’industrie tel que discuté dans la littérature économique, et esquisse des tests empiriques afin de vérifier si les intuitions fournies par les économistes sont en phase avec la réalité de l’industrie.

Que l’économiste envisage les interactions entre le système productif et l’environnement naturel en termes d’externalités ou de bien public, il constate la défaillance du marché à les réguler et la nécessité de l’intervention de l’Etat. Parmi les instruments de régulation disponibles, la fiscalité est le plus efficace économiquement et le plus incitatif à l’innovation. La redistribution du rendement fiscal peut également permettre de rechercher un double dividende et de corriger les inéquités éventuellement engendrées par la régulation.

La littérature sur le double dividende étudie la poursuite simultanée de deux objectifs – l’amélioration de la qualité de l’environnement par l’instauration ou l’augmentation d’une taxe environnementale (premier dividende) et l’augmentation du bien-être social grâce à la diminution des distorsions provoquées par le reste du système fiscal (second dividende). Nous proposons d’aller au-delà des résultats usuels de la littérature, où le second dividende ne peut être atteint qu’au détriment d’un groupe d’agents qui doit supporter la charge de la taxe, en étudiant les conditions à réunir afin de concilier le double dividende avec des critères d’équité. La réforme doit donc atteindre trois objectifs : la qualité de l’environnement, l’efficacité économique (i.e. le gain macroéconomique) et la Pareto amélioration. Cet objectif triple nécessite donc trois instruments : la taxe environnementale, la taxe sur les salaires et l’indice de progressivité fiscale. Nous montrons que les propriétés redistributives de la fiscalité sur les salaires sont un outil de correction des distorsions sociales induites par la politique environnementale. Nous proposons ainsi de recycler les recettes de la fiscalité carbone par une baisse non linéaire de l’impôt sur le revenu qui combine une réduction du taux d’imposition de la première tranche de l’impôt sur le revenu (ce qui bénéficie à tous les agents) et une hausse du taux des tranches supérieures (dont le coût sera supporté par les hauts revenus). Ce dernier mécanisme permet de compenser le caractère régressif de la fiscalité carbone.

We study the Markov-perfect Nash equilibrium (MPNE) of a game between oil-importing countries, who seek to maintain the atmospheric carbon concentration under a given ceiling, and oil-exporting countries. The oil-importing countries set a carbon tax and the oil-exporting countries control the producer price. We obtain implicit feedback rules and explicit non-linear time paths of extraction, carbon tax, and producer price. Consumers are always able to reap some share of the scarcity and monopoly rents, whereas producers partially pre-empt the carbon tax only if the marginal damage under the ceiling is small. We compare the MPNE to the efficient, open-loop, and cartel-without-tax equilibria.

This paper analyzes the environmental tax policy issues when labor is heterogeneous. The objective is to assess whether an environmental tax policy could be Pareto improving, when the revenue of the pollution tax is recycled by a change in the labor tax properties. We show that, depending on the heterogeneity characteristics of labor and on the initial structure of the tax system, a policy mix could be designed in order to leave each class of workers unharmed. It consists of an increase in progressivity together with a decrease in the flat rate component of the wage tax.

Ce texte résume l’expérience de la taxe carbone en Suède : son efficacité environnementale, ses effets distributifs, et les recettes générées par le dispositif.

This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO2) and sulfur dioxide (SO2) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO2 emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO2 emissions. Furthermore, the causality results show that the relationship between income and pollution in Tunisia is one of unidirectional causality with income causing environmental changes and not vice versa, both in the short-run and long-run. This implies that an emission reduction policies and more investment in pollution abatement expense will not hurt economic growth. It could be a feasible policy tool for Tunisia to achieve its sustainable growth in the long-run.

Following Stollery (1998), we extend the Solow– Dasgupta–Heal model to analyze the effects of global warming The rise of temperature is caused by the use of fossil resources so that the temperature level can be linked to the remaining stock of these resources. The rise of temperature affects both productivity and utility. We characterize optimal solutions for the maximin and zero-discounting cases and present closed form solutions for the case where the production and utility functions are Cobb-Douglas, and the temperature level is an exponential function of the remaining stock of resources. We show that a greater weight of temperature in intratemporal preferences or a larger intertemporal elasticity of substitution both lead to postpone resource use.

The aim of this paper is to examine whether the development of waste recycling activities can be a source of economic fluctuations. We assume that the recycling sector has four fundamental characteristics. (i) The production factors are restricted by the production of the last period. (ii) These production factors are waste for which the price determination is noncompetitive. (iii) The sector produces a recycled good, which is a perfect substitute for the primary good. (iv) It reduces the waste stream. We consider the simplest economy, with an infinitely lived agent and a life-cycle hypothesis for the goods. We show that the equilibrium is unique and is always determinate. In spite of the lack of indeterminacy, however, our economy can display cyclical behavior, depending on some usual conditions on parameters. Namely, the steady state may undergo a flip bifurcation or a Hopf bifurcation.

As we begin our final three-year term as editors, we would like to reflect on the learning steep learning curve we have been on for the last five years since we took over the journal on January 1, 2005. This document briefly summarizes our thoughts.

Using survey data of 10,000 households from 10 OECD countries, we identify the driving factors of household adoption of water-efficient equipment by estimating Probit models of a household’s probability to invest in such equipment. The results indicate that environmental attitudes and ownership status are strong predictors of adoption of water-efficient equipment. In terms of policy, we find that households that were both metered and charged for their water individually had a much higher probability to invest in water-efficient equipment compared to households that paid a flat fee.

The objective of this paper is to analyze the efficiency and equity consequences of the implementation of an environmental tax. Do the two purposes collide or can they be simultaneously achieved? Using results of the related literature, we show that precise conditions have to be met in order to achieve three goals: increase of the environmental quality, increase of the economic efficiency and improvement of the intergenerational equity. Are such theoretical conditions likely to occur? What are the rooms of manoeuvre for an environmental tax reform in the European countries? In each of them, the revenues of the existing environmental taxes are low in comparison to the weight of the labor taxes (which are highly distortionary). Using European data, we show that, among all the European countries, Belgium, France and, surprisingly, Sweden, exhibit the less green tax system and offer the easiest opportunity to use the environmental tax as a mean to alleviate the tax burden on labor.

This paper studies the optimal growth of a developing non-renewable natural resource producer. It extracts the resource from its soil, and produces a single consumption good with man-made capital. More- over, it can sell the extracted resource abroad and use the revenues to buy an imported good, which is a perfect substitute of the domes- tic consumption good. The domestic technology is convex-concave, so that the economy may be locked into a poverty trap. We show that the extent to which the country will escape from the poverty trap depends, besides the interactions between its technology and its impatience, on the characteristics of the resource revenue function, on the level of its initial stock of capital, and on the abundance of the natural resource.

In this article, we study the joint dynamics of the demography and the economy. We explore how economic conditions affect fertility choices, and in return how the population growth rate affects both financial and labor markets. Our main contribution is to consider a realistic demographic setup that allows characterizing the age at which individuals decide to give birth to their children. In such a framework, we aim at studying the existence of an equilibrium. We notably prove there exists a monetary steady state if the average age of consumers is greater than the average age of producers.

The aim of this paper is to study the optimal nuclear waste burial policy under an uncertainty: the possibility that an accident might occur in the future. The framework is an optimal growth model with pollution disutility. We show, under some conditions on the waste burial policy, that nuclear power may be a long-term solution for the world energy demand. Under uncertainty on the future safety of the buried waste, the social planner will decide to decrease the rate of waste burying, but the evolution of consumption and hence the evolution of the level of buried waste are ambiguous. Depending on some simple conditions on the balanced growth rate of the economy and on the preference parameters of the households, the optimal amount of buried waste may increase, even if there is a risk of accident in the future.

Cet article analyse les conséquences de la politique environnementale lorsque les agents ont accès à une activité privée de dépollution. Il cherche à comprendre les interactions entre l’engagement privé et l’intervention publique dans la protection de l’environnement. L’étude des conséquences de la politique fiscale sur le stock de capital et la qualité environnementale montre que, selon la nature des inefficiences économiques (sur ou sous-accumulation du capital) et environnementales (sur ou sous-entretien de l’environnement) et les efficacités relatives des techniques de dépollution, les actions publiques et privées doivent se renforcer mutuellement ou se substituer l’une à l’autre.

Contemporary economic analysis is largely subject to rather bizarre schizofrenic syndromes. On the one hand, over the last thirty years or so, macro theories have tried to squeeze the interpretation of whatever aggregate dynamics down to some sort of decision-theoretic framework in which the increasingly mythical ”representative agent” was doing all the action. Whatever statistical properties of the time-series, being it productivity and GDP growth, fluctuations, employment, investment, had to be explained as the equilibrium outcome of some sophisticated inter-temporal maximization exercise by such an agent. Dynamic Stochastic General Equilibrium models are the dominant genre in this spirit. On the micro side largely the opposite has happened. Empirical analyses drawing upon an increasing ensemble of micro longitudinal datasets have powerfully highlighted the ubiquitous, large and persistent heterogeneity in all dimensions of business firms’ characteristics and dynamics one cared to look at.

Cet article analyse les conséquences de la politique environnementale lorsque les agents ont accès à une activité privée de dépollution. Il cherche à savoir si l’engagement privé remet en cause l’intervention publique. Nous montrons que selon (i) les propriétés économiques (sur ou sous-accumulation du capital), (ii) les propriétés environnementales (sur ou sous-entretien de l’environnement) et (iii) les efficacités relatives des techniques de dépollution, les actions publiques et privées doivent être complémentaires ou substituables.

Cette intervention résume l’expérience de la taxe carbone suédoise, ses effets et son efficacité.

Les nombres de demandes de brevets et de “mauvais” brevets accordés ont cru rapidement dans les années récentes. Partant de ce constat, nous étudions le problème de congestion dans le processus d’attribution des brevets et ses conséquences sur les incitations à la R&D pour les entreprises. Nous supposons que le processus d’examen des demandes est imparfait et que sa qualité se dégrade sous l’effet de la congestion. En fonction d’instruments tels que les droits de soumission et la sévérité du critère d’inventivité, le système peut conduire à un équilibre avec forte R&D dans lequel les entreprises s’auto-sélectionnent, ou un équilibre avec peu de R&D, des demandes opportunistes et la délivrance de mauvais brevets. Il y a souvent multiplicité d’équilibres, ce qui limite l’efficacité des instruments de contrôle. On montre comment les conclusions se modifient selon la formalisation de la valeur de la protection par brevet, selon qu’est prise en compte la possibilité de pénalités pour rejet de la demande et selon la force de l’engagement contenu dans la politique de protection des droits de propriété intellectuels.

New technology has been credited with solving environmental problems by mitigating the effects of pollutants. We construct a general equilibrium model in which abatement technology is a real option and pollution’s (negative) amenity value alters both risk aversion and the intertemporal elasticity of substitution. We derive the tax scheme such that in a decentralized economy agents adopt the abatement technology at the time that is socially optimal. We show that the higher the greenness of preferences, the earlier the adoption and the higher the optimal tax rate. We also obtain that adoption is fostered by uncertainty if the effective intertemporal elasticity of substitution is large enough, but is not affected by uncertainty if this elasticity is low. Moreover, the optimal tax rate, which only exists if the effective intertemporal elasticity of substitution is high, is an increasing function of uncertainty.

En 1998, les journées de l’Association Française de Science Économique furent organisées à Toulouse par Michel Moreaux et Michel Mougeot. Certaines des contributions présentées à cette occasion furent ensuite publiées par Économie et Prévision, dans le cadre d’un numéro spécial sur l’Économie de l’Environnement et des Ressources Naturelles(1). Ce numéro paraît dans un cadre identique. Il est lui aussi consacré à l’Économie de l’Environnement et des Ressources Naturelles. Il rassemble une sélection des contributions présentées en juin 2008 lors des Journées Thématiques de l’AFSE, organisées par le LERNA à Toulouse. (1) Économie de l’Environnement et des Ressources Naturelles, numéro d’Économie et Prévision édité par Pierre Malgrange, Michel Moreaux et Michel Mougeot, 143-144, avril-juin 2000.

Les concepts d’épargne véritable et de produit national net, ou vert, apparaissent de plus en plus comme des outils utiles pour apprécier la durabilité de la croissance. L’objectif de l’article est de montrer que la théorie de la croissance en présence de ressources naturelles contribue effectivement à leur donner un fondement, bien qu’elle se heurte à des difficultés pratiques notamment du point de vue de la disponibilité des données. La règle de Hartwick est ici la référence fondamentale. Elle montre que la nullité de l’épargne véritable assure la durabilité de la croissance, dès lors que tous les stocks de capital pertinents ont été pris en compte dans sa définition. Nous mettons en évidence cette propriété dans le modèle canonique de Dasgupta-Heal-Solow, élargi par la prise en compte de l’aménité du capital naturel. Nous élargissons ensuite notre point de vue en supposant que l’environnement économique n’est plus stationnaire : le progrès technique ou la croissance de la population affecte les capacités de production ; les échanges internationaux élargissent le domaine des possibles pour un pays. Nous montrons que des formes adaptées de la règle de Hartwick restent alors valides, mais qu’elles ne se réduisent pas à la nullité de l’épargne véritable usuelle et que leur mise en oeuvre pratique pose des problèmes accrus de disponibilité des données.

Les pays en transition ont considérablement réduit leurs émissions de CO2 entre 1995 et 2003. Cette performance est-elle due à l’application d’une politique volontariste de la part des gouvernements, ou bien est-elle un simple effet collatéral de la transformation industrielle majeure subie par ces pays ? Nous tentons de répondre à cette question en développant deux équations structurelles pour la demande (émissions) et l’offre (politique) de pollution. L’équation de l’offre prend en compte la qualité institutionnelle du pays, aussi bien que les préférences des consommateurs pour la qualité de l’environnement. Nos résultats montrent que, toutes choses égales par ailleurs, l’effet d’échelle de la production seul aurait expliqué une augmentation de 31 % des émissions industrielles de CO2 dans les pays en transition entre 1995 et 2003, et l’effet de structure de la production aurait contribué à une augmentation de 8,4 % de ces émissions. Cependant, l’effet technique, qui découle de la sévérité de la politique environnementale, s’est traduit par une réduction de 58 % des émissions industrielles de CO2, et a permis ainsi une réduction nette des émissions industrielles de CO2 de 18 % en 2003 par rapport à 1995. Enfin, notre étude confirme l’importance des facteurs institutionnels dans l’explication des émissions dans les pays en transition.

L’objectif de ce travail est l’étude du traitement optimal des déchets nucléaires. Nous analysons la politiqued’enfouissement des déchets radioactifs en prenant en considération un risque futur de déstockage accidentel des déchetspréalablement enfouis. Nous montrons que, sous certaines conditions, l’énergie nucléaire peut être une solution delong-terme, malgré l’accumulation des déchets radioactifs. Cette solution nécessite en revanche l’enfouissement d’unepart constante de la production de déchets nucléaires. L’incertitude sur la sécurité des sites d’enfouissement des déchetsconduit naturellement le planificateur social à choisir un taux optimal d’enfouissement des déchets plus faible que celui envigueur en l’absence de risque. Nous montrons en outre que, malgré cette règle de prudence, le stock total de déchetsenfouis peut s’accroître.

Nous étudions les sentiers optimaux du modèle canonique de Dasgupta–Heal–Solow, dans le cas où le taux d’escompte est nul et où le niveau du stock de capital naturel intervient dans la fonction d’utilité. Nous utilisons une règle de Keynes-Ramsey qui permet de généraliser la règle de Hartwick : si la société a un taux d’escompte nul mais accepte une substitution intertemporelle entre niveaux d’utilité, l’investissement net ne doit plus être zéro, comme dans le cas maximin, mais doit être positif et être fixé à un niveau qui dépend de la distance entre le niveau d’utilité de court terme et le niveau de félicité atteint à long terme. Nous caractérisons les solutions optimales dans le cas où l’utilité et la production sont Cobb-Douglas et nous analysons l’influence de l’élasticité intertemporelle de substitution sur le profil temporel du sentier optimal. Nous montrons aussi que, dans ce cas Cobb-Douglas, la valeur relative des stocks de ressource et de capital reste constante sur le sentier optimal, à un niveau qui ne dépend pas des conditions initiales.

Simultaneity between commitment periods (2008-2012) of the International Emissions Trading scheme and the European Emissions Trading Scheme is likely to generate distortions in terms of burden distribution among sectors. There will be two levels of trading (a country and an entity level), which both need to be consistent with one another. Besides, features of these two schemes are different. Thus, to reach international targets, each European government will have to adopt an additional policy. It may consist in implementing a tax on emissions of sectors non-covered by EU-ETS. The level of this tax depends on the effort realized within the European market. We propose a modeling of this two-level environmental policy, focusing on the additional tax rates and introducing several cases of linkages. We obtain empirical estimations of the efforts that could be demanded to non-covered sectors, and of the price(s) of carbon. We show that the opportunities of trading provided by the international market alleviate the burden supported by non-covered sectors.

We investigate the European food market in two selected European countries, Great Britain and Denmark, identifying main differences and similarities. We focus particularly on consumer perceptions and priorities, labelling schemes, and sales channels as a basis for assessing market stability and prospects for future growth. We employ a unique set of household panel data that includes information on stated values and concerns as well as registered purchasing behaviour. Most organic food on both markets is produced and processed by large-scale industrialised units and distributed through mainstream sales channels, consumer confidence being sustained at present by organic labelling schemes that appear to function well. However, a parallel market, based on the supply of goods through various direct sales channels to heavy users, prevails. We find that organic food purchase decisions are primarily motivated by ‘private goods’ attributes such as freshness, taste and health benefits, attributes that may be perceived as being compatible with modern production and sales structure. Mature markets for organic foods nevertheless appear to be vulnerable to consumer dissatisfaction, particularly among heavy users of organic food products.

This paper studies the maximin paths of the canonical Dasgupta-Heal-Solow model when the stock of natural capital is a direct argument of well-being, besides consumption. Hartwick’s rule then appears as an efficient tool to characterize solutions in a variety of settings. We start with the case without technical progress. We obtain an explicit solution of the maximin problem in the case where production and utility are Cobb-Douglas. When the utility function is CES with a low elasticity of substitution between consumption and natural capital, we show that it is optimal to preserve forever a critical level of natural capital, determined endogeneously. We then study how technical progress affects the optimal maximin paths, in the Cobb-Douglas utility case. On the long run path of the economy capital, production and consumption grow at a common constant rate, while the resource stock decreases at a constant rate and is therefore completely depleted in the very long run. A higher amenity value of the resource stock leads to faster economic growth, but to a lower long run rate of depletion. We then develop a complete analysis of the dynamics of the maximin problem when the sole source of well-being is consumption, and provide a numerical resolution of the model with resource amenity. The economy consumes, produces and invests less in the short run if the resource has an amenity value than if it does not, whereas it is the contrary in the medium and long runs. However, and without surprise, the resource stock remains for ever higher with resource amenity than without.

The Kyoto Protocol, which came into force in February 2005, allows countries to resort to ‘supplementary activities’, consisting particularly in carbon sequestration in agricultural soils. Existing papers studying the optimal carbon sequestration recognize the importance of the temporality of sequestration, but overlook the fact that it is an asymmetric dynamic process. This paper takes explicitly into account the temporality of sequestration. Its first contribution lies in the modelling of the asymmetry of the sequestration/de-sequestration process at a micro level, and of its consequences at a macro level. Its second contribution is empirical. We compute numerically the optimal path of sequestration/de-sequestration for specific damage and cost functions, and a calibration that mimics roughly the world conditions. We show that with these assumptions sequestration must be permanent, and that the error made when sequestration is supposed immediate can be very significant.

We estimate hurdle rates for firms’ investments in pollution abatement technology, using ex post data. The method is based on a structural option value model where the future price of polluting fuel is the major source of uncertainty facing the firm. The empirical procedure is illustrated using a panel of firms from the Swedish pulp and paper industry, and the energy and heating sector, and their sulfur dioxide emissions over the period 2000-2003. The results indicate that hurdle rates of investment vary from 2.7 to 3.1 in the pulp and paper industry, and from 3.4 to 3.6 in the energy and heating sector depending on econometric specification.

Our intention is to study, in the framework of a very simple optimal growth model, the consequences on the optimal paths followed by consumption and the environmental quality of an endogenous discounting. Consumption directly comes from the use of environmental services and so is a direct cause of environmental degradation. The environment is valued both as a source of consumption and as an amenity. For a sustainability concern, we introduce an endogenous discount rate growing with the environmental quality, and compare the optimal growth paths with the ones obtained in the usual case of exogenous and constant discounting. We show that the convergence of the environmental quality towards a steady state occurs only for a very special configuration of the parameters in the exogenous discounting case, while it occurs generically in the endogenous discounting one. This happens for a utility discount rate becoming suficiently high when the environmental quality is high and suficiently low when the environmental quality is poor. In this case then, endogenous discounting with a positive marginal discount rate allows us to avoid the depletion of the environment.

Simultaneity between commitment periods (2008-2012) of the International Emissions Trading scheme and the European Emissions Trading Scheme is likely to generate distortions in terms of burden distribution among sectors. There will be two levels of trading (a country and an entity level), which both need to be consistent with one another. Besides, features of these two schemes are different. Thus, to reach international targets, each European government will have to adopt an additional policy. It may consist in implementing a tax on emissions of sectors non-covered by EU-ETS. The level of this tax depends on the effort realized within the European market. We propose a modeling of this two-level environmental policy, focusing on the additional tax rates and introducing several cases of linkages. We obtain empirical estimations of the efforts that could be demanded to non-covered sectors, and of the price(s) of carbon. We show that the opportunities of trading provided by the international market alleviate the burden supported by non-covered sectors.

L’environnement est aujourd’hui au coeur des préoccupations mondiales. Tous les domaines de la recherche sont concernés et doivent, dans une logique de coopération qui ne va pas de soi, prendre en compte l’ensemble des implications de la question. D’où ce dictionnaire transdisciplinaire. Aux entrées générales (climats, géosystème, glaciers), sont associées d’autres en phase avec les grands problèmes actuels (changement climatique, déforestation, ouragan) et des notices plus originales relevant de l’économie (commerce équitable, écotourisme, sous-développement), de l’histoire (du risque, de l’écologie ou de l’architecture), du droit et de la science politique (principe de précaution, loi paysage, gestion des risques).

The paper explores strategies that the sponsor of a proposal may employ to convince a qualified majority of members in a group to approve the proposal. Adopting a mechanism design approach to communication, it emphasizes the need to distill information selectively to key group members and to engineer persuasion cascades in which members who are brought on board sway the opinion of others. The paper shows that higher congruence among group members benefits the sponsor. The extent of congruence between the group and the sponsor, and the size and the governance of the group, are also shown to condition the sponsor’s ability to get his project approved.

Dans les organisations privées ou publiques, les décisions sont souvent prises par des groupes. L’article analyse les stratégies que peut utiliser l’initiateur d’un projet pour convaincre une majorité (qualifiée) de membres du groupe d’adopter ce projet. L’article étudie des mécanismes de communication; il met l’accent sur la possibilité de diffuser de manière sélective l’information à des acteurs clés du groupe, et sur la possibilité d’enclencher des “cascades de persuasion” dans lesquelles les membres qui sont convaincus de l’intérêt du projet entraîne l’adhésion des autres. L’article identifie les facteurs qui déterminent les chances d’approbation du projet par le groupe: la convergence d’intérêt entre les membres du groupe, la convergence d’intérêt entre le groupe et l’initiateur du projet, la taille du groupe et les règles de décision collectives.