Publications des chercheurs de PSE

We document majority support for policies entailing global redistribution and climate mitigation. Recent surveys on 40,680 respondents in 20 countries covering 72% of global carbon emissions show strong support for an effective and progressive way to combat climate change and poverty: a global carbon price funding a global basic income, called the "Global Climate Scheme" (GCS). Using complementary surveys on 8,000 respondents in the U.S., France, Germany, Spain, and the UK, we test several hypotheses that could reconcile strong stated support with a lack of salience in policy circles. A list experiment shows no evidence of social desirability bias, majorities are willing to sign a real-stake petition, and global redistribution ranks high in the prioritization of policies. Conjoint analyses reveal that a platform is more likely to be preferred if it contains the GCS or a global tax on millionaires. Universalistic attitudes are confirmed by an incentivized donation. In sum, our findings indicate that global policies are genuinely supported by a majority of the population. Public opinion is therefore not the reason that they do not prominently enter political debates.

In 2015, the Sustainable Development Goals set the eradication of extreme poverty by 2030 as a universally agreed objective. This paper analyses the prospects for achieving this goal country by country. Without a reduction in inequality, even with a very optimistic annual growth rate of 7% between 2022 and 2030, 3% of humans would still be living in extreme poverty in 2030. National capacity to eradicate poverty is then measured using the concepts of antipoverty cap or antipoverty tax required to finance poverty eradication, and income floor (financed by a given income tax). With credible annual growth of 3%, even capping incomes at $7 a day cannot eradicate extreme poverty in 5 low-income countries. In other words, neither growth alone nor growth combined with radical domestic redistribution could eradicate extreme poverty by 2030. By contrast, a transfer of just 0.14% of global income could achieve this goal.

We conduct surveys on both participants in the French Citizens Convention for Climate (CCC) and the general public. By comparing the answers of the randomly drawn citizens with those of the general population on identical questions, we assess the representativity of the CCC, study the evolution of the citizens' opinions, and document the perceptions of the CCC. The CCC appeared broadly representative of the French population. Although, the CCC's Citizens seemed to have been somewhat more favorable to climate policies than the general population at the start, a majority support was found for all proposed measures but one. Despite our findings that the CCC correctly represented the population, we document widespread ignorance and mistrust towards the CCC, including a largely shared belief that it was not representative.

This paper follows van der Ploeg (Metroeconomica 37(2):221–230, 1985)’s research program in testing both its extension of Goodwin (in: Feinstein (ed) Socialism, capitalism and economic growth, Cambridge University Press, Cambridge, 4, 54–58, 1967) predator–prey model and the Minsky Financial Instability Hypothesis (FIH) proposed by Keen (J Post Keynes Econ 17(4):607–635, 1995). By endowing the production sector with CES technology rather than Leontief, van der Ploeg showed that the possible substitution between capital and labor transforms the close orbit into a stable focus. Furthermore, Keen (1995)’s model relaxed the assumption that profit is equal to investment by introducing a nonlinear investment function. His aim was to incorporate Minsky’s insights concerning the role of debt finance. The primary goal of this paper is to incorporate additional properties, inspired by van der Ploeg’s framework, into Keen’s model. Additionally, we outline possibilities for production technology that could be considered within this research program. Using numerical techniques, we show that our new model keeps the desirable properties of Keen’s model. However, we also demonstrate that when the economy is endowed with a class of CES production function that includes the Cobb–Douglas and the linear technology as limit cases, the unique stable equilibrium is an economically desirable one. Finally, we propose a modified extension that includes speculative component in the economy as in Grasselli and Costa-Lima (Math Financ Econ 6(3):191–210, 2012) and investigate its effect on the dynamics. We conclude that CES production function is a more suitable assumption for empirical purposes than the Leontief counterpart. Finally, we show, using numerical simulations, that under plausible calibration, the model endowed with CES production function eventually lose the cyclical property of Goodwin’s model with and without the speculative component.

The EROI – for Energy Returned On Invested – of an energy technology measures its ability to provide energy efficiently. Previous studies draw a link between the affluence of a society and the EROI of its energy system, and show that EROIs of renewables are lower than those of fossil fuels. Logically, concerns have been expressed that system-wide EROI may decrease during a renewable energy transition. First, I explain theoretically that the EROIs of renewables themselves could then decrease as energy-efficient fossil fuels would be replaced by less energy-efficient renewables in the supply-chain. Then, using the multi-regional input-output model THEMIS, I estimate the evolution of EROIs and prices of electric technologies from 2010 to 2050 for different scenarios. Global EROI of electricity is predicted to go from 12 in 2010 to 11 in 2050 in a business-as-usual scenario, but down to 6 in a 100% renewable one. Finally, I study the economic implication of a declining EROI. An inverse relation between EROI and price is suggested empirically, even though theory shows that both quantities may move in the same direction.

This paper helps to understand how beliefs form and determine attitudes towards policies. Using a new survey and official households’ survey data, we investigate the case of carbon taxation in France in the context of the Yellow Vests movement that started against it. We find that French people would largely reject a Tax & Dividend policy, i.e. a carbon tax whose revenues are redistributed uniformly to each adult. However, they also overestimate the negative impact of the scheme on their purchasing power, wrongly think it is regressive, and do not perceive it as environmentally effective. Using information about the scheme as instruments to robustly identify causal effects, our econometric analysis shows that if we could rectify these three biased beliefs, it would suffice to generate majority approval. Yet, only a small minority can be convinced by new information and revisions are biased towards pessimism. Finally, if overly pessimistic beliefs cause tax rejection, they also result from it through motivated reasoning, which manifests what we define as “tax aversion”.

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.

This paper aims to assess the prospects for French climate policies after the Yellow Vests crisis halted the planned increase in the carbon tax. From a large representative survey, we elicit knowledge, perceptions and values over climate change, we examine opinions relative to carbon taxation, and we assess support for other climate policies. Specific attention is given to the link between perceptions of climate change and attitudes towards policies. The paper also studies in detail the determinants of attitudes in terms of political and socio-demographic variables. Among many results, we find limited knowledge but high concern for climate change. We also document a large rejection of the carbon tax but majority support for stricter norms and green investments, and reveal the rationales behind these preferences. Our study entails policy recommendations, such as an information campaign on climate change. Indeed, we find that climate awareness increases support for climate policies but no evidence for the formation of opinions through partisan cues as in the US, suggesting that better access to science could foster support for climate policies.

Cette thèse s'interroge sur les conditions de réalisation d'une civilisation industrielle décarbonée et durable, en étudiant certains aspects de sa faisabilité physique et de son acceptabilité politique. Le Chapitre I étudie l'évolution du taux de retour énergétique dans différents scénarios prospectifs, et prédit que l'efficacité globale du secteur de l'électricité à fournir un surplus d'énergie serait réduite de moitié dans un scénario 100% renouvelable. Le Chapitre 2 souligne l'importance de la recyclabilité des métaux dans un modèle d'extraction optimale des métaux et des fossiles pour la production d'énergie. L'annexe au Chapitre 2 étend le théorème de Karush-Kuhn-Tucker au cas d'une série convexe sous un nombre fini de contraintes. Les Chapitres 3 et 4 se fondent sur une enquête auprès d'un échantillon représentatif de trois milles français, réalisée durant le mouvement des Gilets jaunes. Le Chapitre 3 étudie les croyances relatives à une taxe carbone avec dividende, mesure vantée pour lutter contre le changement climatique du fait de son efficacité et de sa progressivité. Si 70 % rejettent la taxe avec dividende. c'est en raison de perceptions pessimistes quant à ses propriétés : en contradiction avec les micro-simulations effectuées, la plupart pensent que leur ménage perdrait en pouvoir d'achat suite à la réforme, la perçoivent comme régressive et inefficace pour réduire la pollution et lutter contre le changement climatique. Le Chapitre 4 analyse les connaissances, les perceptions et les valeurs liées au changement climatique, examine les opinions relatives à la taxation du carbone et évalue le soutien à d'autres politiques climatiques.

The paper deals with voting rules that require voters to rate the candidates on a finite evaluation scale and then elect a candidate whose median grade is maximum. These rules differ by the way they choose among candidates with the same median grade. Call proponents (resp. opponents) of a candidate the voters who rate this candidate strictly above (resp. strictly below) her median grade. A simple rule, called the typical judgment, orders tied candidates by the difference between their share of proponents and opponents. An appealing rule, called the usual judgment, divides this difference by the share of median votes. An alternative rule, called the central judgment, compares the relative shares of proponents and opponents. The usual judgment is continuous with respect to these shares. The majority judgment of Balinski & Laraki (2007) considers the largest of these shares and loses continuity. A result in Balinski & Laraki (2014) aims to characterize the majority judgment and states that only a certain class of functions share some valuable characteristics, like monotonicity. We relativize this result, by emphasizing that it only holds true for nondiscrete scales of grades. Properties remaining specific to the majority judgment in the discrete case are idiosyncratic features rather than universally sought criteria, and other median-based rules exist that are both monotonic and continuous.

Les citoyens membres de la Convention Citoyenne pour le Climat (CCC) sont-ils représentatifs des Français ? Ces derniers approuvent-ils les politiques climatiques proposées par la Convention ? Cette note aborde ces questions en comparant les points de vue des citoyens de la Convention avec ceux d’échantillons représentatifs de la population générale interrogés avant que les mesures proposées par la CCC soient diffusées publiquement.