Publications by PSE researchers

Taxing sugary drinks is a public health measure that has been enacted in a growing number of jurisdictions over the past 15 years. This intervention needs to be evaluated, and its aims clarified. Based on the results of a multidisciplinary research project, in this article we report on the conditions that led to the revision of the taxation of sugar-sweetened beverages in France in 2018. We found an intention to improve the nutritional quality of the beverage offer rather than directly influence consumer behavior. We discuss some of the effects associated with the tax implementation.

In order to promote healthier diets, public authorities are taking action to better inform consumers, encourage manufacturers to improve the nutritional composition of their products, and control the marketing of these products. In recent years, the taxation of foods and beverages with unhealthy nutritional profiles has been one of the measures attracting interest. Taxing sugary drinks, or the “soda tax”, is one of the measures recommended by the World Health Organization (WHO) (WHO 2022). In France, a soda tax was introduced in January 2012. Modified in July 2018, it is now indexed to the added sugar content in the drink (Ministry of Public Action and Accounting 2018). At a time when other countries are considering whether to introduce or optimize such a measure, this change provides an opportunity to learn from its development, implementation and effects on supply and consumption. This is the perspective behind the Soda-Tax research project (2019-2023), coordinated by the Ecole des hautes études en santé publique (EHESP) in collaboration with the Paris School of Economics, the Institut National de la Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), the Université Sorbonne Paris Nord (USPN), and Nantes Université. This project was co-funded by the Ligue Contre le Cancer as part of the Institut pour la Recherche en Santé Publique (IReSP) general call for projects – prevention and health promotion component 2018. This report summarizes the results of the research. Some of them have already been published. Other results will be submitted in the coming months to scientific journals whose peer review process could in some cases lead them to evolve. These results are therefore communicated here on a preliminary basis, with the dissemination of this report intended to inform the steering of the measure and the interested parties in a more timely manner.

This paper investigates the association between several mental health indicators (depression, anxiety, stress, and loneliness) and the overall tendency to follow official recommendations regarding self-protection against COVID-19 (i.e., overall compliance). We employ panel data from the COME-HERE survey, collected over four waves, on 7,766 individuals (22,878 observations) from France, Germany, Italy, Spain, and Sweden. Employing a flexible specification that allows the association to be non-monotonic, we find a U-shaped relationship, in which transitions to low and high levels of mental health are associated with higher overall compliance, while transitions to medium levels of mental health are associated with less overall compliance. Moreover, anxiety, stress, and loneliness levels at baseline (i.e., at wave 1) also have a U-shaped effect on overall compliance later (i.e., recommendations are followed best by those with lowest and highest levels of anxiety, stress, and loneliness at baseline, while following the recommendations is lowest for those with moderate levels of these variables). These U shapes, which are robust to several specifications, may explain some of the ambiguous results reported in the previous literature. Additionally, we observe a U-shaped association between the mental health indicators and a number of specific health behaviours (including washing hands and mask wearing). Importantly, most of these specific behaviours play a role in overall compliance. Finally, we uncover the role of gender composition effects in some of the results. While variations in depression and stress are negatively associated with variations in overall compliance for men, the association is positive for women. The U-shaped relation in the full sample (composed of males and females) will reflect first the negative slope for males and then the positive slope for females.

Objectives: Consideration of future consequences (CFC) distinguishes individuals who adopt behaviors based on immediate needs and concerns from individuals who consider the future consequences of their behaviors. We aimed to assess the association between CFC and diet, and testing the mediating role of food choice motives on this relationship. Design: Individuals (age≥18 years) completed the CFC-12 questionnaire in 2014, at least three 24-h dietary records, and a food choice motive questionnaire. A multiple mediator analysis allowed to assess the mediating effect of food choice motives on the cross-sectional association between CFC and diet, adjusted for socio-demographic factors. Setting: Data from the NutriNet-Santé cohort study. Participants: 27,330 participants. Results: CFC was associated with all food choice motives (P < 0.001), with the strongest positive associations for avoidance for environmental reasons, absence of contaminants and health motives, and the strongest negative associations for innovation and convenience). Positive total effects were found between CFC and the consumption of healthy food groups (fruits and vegetables, whole-grain foods, legumes); and negative total effects for alcohol, meat and poultry and processed meat (P < 0.001). CFC was positively associated with diet quality (P < 0.001). Across food groups, major mediators of these relationships were higher health (8.4-32.6%), higher environmental (13.7-22.1 %) and lower innovation (7.3-25.1 %) concerns. Conclusions: CFC was associated with healthier dietary intake, essentially mediated by a greater motivation of future-oriented participants for self-centered and altruistic outcomes, including health and environment. Focusing on the awareness of future benefits in public health interventions might lead to healthier dietary behaviors.

Food prices have been rising sharply for over a year now. The provisional results published by Insee in January 2023 show an increase of of 13.2% since January 2022, more than double the rise in the price index (+6%) and slightly slightly less than energy prices (+16%) [1]. Detailed data published by IRI show that price rises have particularly affected staple foods and "bottom-of-the-range bottom-of-the-cupboard" products, such as oils, rice, sugar or minced steaks [2]. Prices for "first-price" and private-label products are rising more sharply than national brands (+17.8% for the former and +11.6% for the latter the latter [3]), probably due to lower margins, which mean that the increase in more directly on the final price. The causes of these price rises are multiple and well identified. First of all, they are due to shocks to agricultural and food production at international level and to the logistics of distribution chains: war in Ukraine, disruption of logistics chains linked to the Covid-19 pandemic and geopolitical tensions, impacts of meteorological disasters linked to global warming such as the floods in Pakistan. Secondly, growing food demand in certain countries, notably China, is structurally destabilizing agri-food markets, partly as a result of the Chinese government's policy of ensuring food security through stockpiling, without coordination with other countries [4]. What could be the consequences of these brutal price hikes on the choices of French consumers, particularly the most disadvantaged?

Public health authorities advocate the introduction of alcohol pricing policies in the form of tax reform and/or a minimum unit price based on the pure alcohol content of products. We use Kantar WorldPanel household purchase data to describe the distortions in the current tax system, favouring wine and penalising low-income households. We assess the potential impact of reform sce­narios that replace current taxes with a single excise tax (flat or progressive) on pure alcohol content and/or the introduction of a minimum price per gram of pure alcohol. Introducing a minimum price while leaving taxation unchanged would have the advantage of raising alcohol prices, especially for low-end wines, which are prized by abusive consumers. The impact would a priori be limited in terms of tax regressivity and for higher quality segments, which is important for the wine sector.

Is the psyche of individuals susceptible to change during “crises”? Or conversely, to paraphrase Stigler and Becker [1977], are individual preferences “rock solid”, in other words, stable over time? Even if, theoretically, economists favor preference stability over instability, knowing whether “shocks,” whether demographic, health, natural, conflict or economic, are likely to modify the parameters of individuals’ tastes and, consequently, their behavior, is an important question for public policy. Many empirical studies now seek to test whether or not preferences change over time, or whether they are durably modified by life events or structural shocks faced by individuals. The conclusions depend on the origin of the shocks, the methodology adopted to measure preferences and the nature of the questions asked. The 2020 Covid-19 pandemic shock is a new opportunity to study this question of taste stability. There are already many studies that have analyzed the impact of the Covid crisis on savers, but they do not reach a consensus on the meaning of the impact of the health crisis on preferences. For France, the statistical treatments carried out here on the basis of the Pat€r 2020 survey show a stability of risk preferences: The “great containment” would thus have had little impact on savers’ preferences.

La psyché des individus est-elle susceptible de changer pendant les « crises » ? Ou inversement, pour paraphraser Stigler et Becker (1977), les préférences individuelles sont-elles « solides comme un roc », en d’autres termes, stables temporellement ? Même si théoriquement, les économistes privilégient la stabilité des préférences à l’instabilité, savoir si des « chocs », qu’ils soient démographiques, sanitaires, naturels, conflictuels ou économiques, sont susceptible de modifier les paramètres de goût des individus et en conséquence leurs comportements, est une question importante en matière de politique publique. De nombreux travaux empiriques cherchent aujourd’hui à tester si les préférences évoluent ou non dans le temps, ou encore si elles sont durablement modifiées par des événements de la vie ou des chocs structurels auxquels sont confrontés les individus. Les conclusions dépendent de l’origine des chocs, de la méthodologie adoptée pour mesurer les préférences et de la nature des questions posées. Le choc de la pandémie du Covid-19 de 2020 est une nouvelle opportunité pour étudier cette question de la stabilité des goûts. Il existe déjà de nombreuses études qui ont analysé l’impact de la crise du Covid sur les épargnants mais qui n’aboutissent à aucun consensus sur le sens de l’impact de la crise sanitaire sur les préférences. Pour la France, les traitements statistiques réalisés ici à partir de l’enquête Pat€r 2020 montrent plutôt une stabilité des préférences vis-à-vis du risque : le « grand confinement » n’aurait ainsi eu que peu d’impact sur les préférences de l’épargnant.

Introduction There is a lack of quantitative evidence on the role of food innovations—new food ingredients and processing techniques—in the nutrition transition. Objective Document the distribution of food innovations across 67 high-income (HIC) and middle-income (MIC) countries between 1970 and 2010, and its association with the nutritional composition of food supply. Methods We used all available data on food patents, as compiled by the European Patent Office, to measure food innovations. We considered innovations directly received by countries from inventors seeking protection in their territories, and those embedded in processed food imports. Food and Agricultural Organization data were used to estimate the associations between international diffusion of food innovations and trends in total food supply and its macronutrient composition, after adjusting for confounding trends in demand-side factors. We identified the role of trade by simulating the changes in average diet due to innovations embedded in food imports. Results Trends in food innovations were positively and significantly associated with changes in daily per capita calorie supply available for human consumption in MIC between 1990 and 2010 (elasticity of 0.027, 95% CI 0.019 to 0.036). Food innovations were positively correlated with the share of animal and free fats in total food supply (elasticities of 0.044, 95% CI 0.030 to 0.058 for MIC between 1970 and 1989 and 0.023, 95% CI 0.003 to 0.043 for HIC between 1990 and 2010). Food innovations were associated with substitutions from complex carbohydrates towards sugars in total food supply for MIC after 1990 (elasticities of −0.037, 95% CI −0.045 to −0.029 for complex carbs, 0.082, 95% CI 0.066 to 0.098 for sugars). For these countries, the trade channel capturing access to innovations through imports of processed food played a key role. Conclusion Policy-makers should consider the impacts of the international diffusion of food innovations in assessing the costs and benefits of international trade regulations.

The COVID-19 outbreak has generated significant uncertainty about the future, especially for young adults. Health and economic threats, as well as more diffuse concerns about the consequences of COVID-19, can trigger feelings of anxiety, leading individuals to adopt uncertainty-reducing behaviours. We tested whether anxiety was associated with an increase in willingness to be exposed to the risk of COVID-19 infection (WiRE) using an online survey administered to 3,110 French individuals aged between 18 and 35 years old during the first pandemic wave and lockdown period (April 2020). Overall, 56.5% of the sample declared a positive WiRE. A one standard deviation increase in psychological state anxiety raised the WiRE by +3.9 pp (95% CI [+1.6, 6.2]). Unemployment was associated with a higher WiRE (+8.2 percentage points (pp); 95% CI [+0.9, 15.4]). One standard deviation increases in perceived hospitalisation risk and in income (+1160€) were associated with a -4.1 pp (95% CI [-6.2, 2.1]) decrease in the WiRE and +2.7 pp increase (95% CI [+1.1, 4.4]), respectively. Overall, our results suggest that both psychological anxiety and the prospect of economic losses can undermine young adults’ adherence to physical distancing recommendations. Public policies targeting young adults must consider both their economic situation and their mental health, and they must use uncertainty-reducing communication strategies.

This contribution reviews the main normative and positive arguments that can used in the assessment of the costs and benefits of food marketing restrictions, focusing specifically on theoretical and empirical developments in the economics of advertising, consumer behaviour and industrial organization since the 70s.

In 2016, the World Health Organization officially recommended sugar-sweetened beverage (SSB) taxation as a strategy to reduce purchases, stimulate product reformulation and generate revenues for health-related programmes. Four years before, France had been one of the first countries to tax SSBs. However, the design of this tax was not considered optimal: its rate was flat, low, identical for SSBs and artificially-sweetened drinks containing no added sugars, and its initial public health justification was set aside in favour of budgetary concerns. In 2018, a new taxation scheme was enacted. Integrated in the Social Security Finance Bill, the tax on SSBs is now linearly indexed to the quantity of added sugars in the drink. In this article, we summarize the lessons learnt from the 2012 soda tax and offer insights on the potential public health benefits of the new tax enacted in 2018. A multidimensional framework aimed at gathering evidence about SSB taxation for public health drove our rational so that we address: (1) the soda tax policy-change process; (2) its impact on price and purchases; (3) the consumer receptiveness to the tax and; (4) its legal framework. We also discuss the potential application of the tax to other foods/nutrients.