Research

WORKING papers

International Attitudes Toward Global Policies, with Thomas Douenne & Linus Mattauch. slides

Outreach: Foreign Policy, Civicus

We find strong and sincere support for global redistributive policies in the 20 countries surveyed. In particular, there is majority support for the "GCS": a global carbon price funding a global basic income; in France, a left-wing candidate would even win 11 points in the Presidential election by endorsing this policy. There is also strong majority support for a global wealth tax. In the U.S. and Europe, the median preferred share of the wealth tax that should fund low-income countries is 30%. We also study attitudes toward climate burden-sharing and foreign aid.

Shortfall of Domestic Resources to Eradicate Extreme Poverty by 2030

With credible annual growth of 3%, even capping incomes at $7 a day cannot eradicate extreme poverty in the lowest-income countries. Neither growth alone nor growth combined with radical internal redistribution can eradicate extreme poverty by 2030. By contrast, a transfer of just 0.14% of global income could achieve this goal.

Fighting Climate Change: International Attitudes Toward Climate Policies, with Antoine Dechezleprêtre, Tobias Kruse, Bluebery Planterose, Ana Sanchez Chico & Stefanie Stantcheva. 

Surveying 40,680 people in 20 countries, we document strong support for climate action. We confirm that three motives are key for accepting a climate policy: perceiving it as effective, fair, and in one's interest. Some policies such as a national carbon tax with cash transfers are less supported than others (including other variants of a carbon tax), notably due to pessimistic perceptions of their costs. 

slides 20' video 1h video VoxEU NBER

Disagreement Aversion, with Antoine Bommier, Arnaud Goussebaïle & Daniel Heyen

Decision-makers rely on experts who often disagree. Aversion to expert disagreement is usually modelled with ambiguity-averse preferences which rest on a unanimity principle: if all experts agree that one choice is better than another, so should the decision-maker. Such unanimity among experts however can be spurious, masking substantial disagreement on the underlying reasons. We introduce a novel notion of disagreement aversion which allows to distinguish spurious from genuine unanimity. We develop a model centered around the cautious aggregation of expert beliefs that is able to capture that novel notion of disagreement aversion. We provide formal results and illustrate them in applications. 

Publications

“Co-construction” in deliberative democracy: lessons from the French Citizens’ Convention for Climate, with Louis-Gaëtan Giraudet et al., 2022, Humanities and Social Sciences Communications

Yellow Vests, Pessimistic Beliefs, and Carbon Tax Aversion, with Thomas Douenne, 2022, American Economic Journal: Economic Policy

Why do 70% of French people reject a carbon tax and dividend policy? Because they have biased perceptions about its effectiveness, progressivity, and about its impact on their purchasing power. Only few of our 3,002 respondents correct their biases when information is provided, but those who do largely approve the tax.

Video 10' (20', 40'), Presentation (short), codes and graphics on github, Open Version
Les Français et la taxe carbone (enquêtes complémentaires un an après) : présentation courte, longue

Opinions des Français sur les politiques climatiques, avec Thomas Douenne, 2019, Document de travail du Cepremap

Notre enquête sur un échantillon représentatif de 3000 Français éclaire sur leurs perceptions et préférences par rapport aux politiques climatiques. Elle met en évidence le rejet des taxes pigouviennes, mais dégage des mesures populaires : investissements et normes écologiques.

Tie-breaking the Highest Median: Alternatives to the Majority Judgment, 2020, Social Choice & Welfare

Majority Judgment (MJ) is a voting system rewarding the choice with the highest median grade. Balinski & Laraki show that MJ holds remarkable properties: IIA, minimizing manipulability, etc. I revise one of their result stating that only peculiar tie-breaking rules carry a desirable property, and propose other credible tie-breaking rules. I call the simplest one the typical judgment. R package

French Attitudes over Climate Change and Climate Policies, with Thomas Douenne, 2020, Ecological Economics

[companion paper to supra] French people have limited knowledge but high concern over climate change. Knowledge and perceived danger of CC is associated with more ecological policy preferences. Most people reject the carbon tax but approve a deep transition if: it is global, the rich contribute, and alternatives are provided. And many more results. Open version

Perceived impacts of CC (top). Possibility to switch commuting mode for drivers (bottom).

Geoengineering In Climate Negotiations, with Gernot Wagner, 2020, Humanities & Social Sciences Communications

Our game theoretic model shows that, if some countries face moderate impacts of a low level of mitigation but fear the uncertain consequences of geoengineering, they could agree for a high mitigation policy in order to avoid the deployment of geoengineering by countries facing disastrous damages of climate change. Podcast interview

Mineral Resources for Renewable Energy: Optimal Timing of Energy Production, with Mouez Fodha and Francesco Ricci, 2020, Resource and Energy Economics

We study the optimal timing of extraction of two finite resources in infinite horizon: minerals, which are recyclable, and fossils, which are not (and which are polluting in an extension). Among other results, we show that the higher the recyclability, the sooner we should extract minerals.

Open version, Presentation

Is Green Electricity Sustainable? Estimation of EROIs Until 2050, 2019, Ecological Economics

The EROI measures the ability to provide energy efficiently, and some studies relate it to the affluence of a society. I estimate that global EROI of electricity should decrease from 12 in 2010 to 11 in 2050 in a trend-based scenario or 6 in a 100% renewable one. In a theoretical analysis, I show that EROI and price can decrease at the same time, which weakens the idea that a declining EROI should lead to a recession. 

Open version, presentation, notebook, general public notebook

Karush-Kuhn-Tucker theorem in infinite dimension, with Mohammed Bachir and Sebastian Tapia-García, 2021, Advances in Operator Theory

We derive conditions for optimality and Gâteaux differentiability of convex functions in certain spaces of infinite dimension. The Karush-Kuhn-Tucker theorem naturally extends to the case of a convex function with a countable number of variables (such as series) and a finite number of constraints. Thus, under minimal hypotheses, a solution of first order conditions of an infinite horizon Lagrangian is necessarily an optimum. Old, open version, Ready-to-use theorem

French Favored Redistribution Derived From Surveys, 2022, Revue économique

It is often thought that the level of redistribution entailed by a country's tax system reflects the preferences of its citizens. However, survey evidence invalidates this view. This raises a crucial question for policymaking: “What redistribution would (a majority of) people support?”. Using two ad-hoc surveys, the most precise answer to date is provided using an original method which quantifies desired income tax rates, and which is in turn used to assess the political acceptability of the optimal tax theory. In the first survey, respondents picked their preferred values for parameters which were used to determine the shapes of redistributions. Using different algorithms, several redistributions were derived from the interpolation of the median choices of each parameter (50% of winners, 10% of losers and a monthly demogrant of 800€). In the second survey, a majority of respondents agreed on implementing these redistributions. Interestingly, the average desired redistribution corresponds closely to the shape of the optimal taxation derived from an utilitarian criterion. This allowed to show that this redistribution fails to obtain a significant majority support (contrarily to others), despite its good reception in a setting inhibiting self-interest. 

Open Version, French version, presentation (french), codes and data

Median desired redistribution (from the current one in red to the green curve).

Median desired redistribution (from the current one in red to the green curve).

Minskyan Classical Growth Cycles, with Florent Mc Isaac and Daniel Bastidas, 2019, Mathematics and Financial Economics

We introduce substitutability in the Keen model, which builds upon Minsky's insights by adding a debt dynamic in the Goodwin model of cyclical profit and unemployment. With a CES production function rather than a Leontief, the cycles are dampened. We study and interpret the system and its multiple equilibra, and derive numerically its basins of attraction. Open version

Working papers

PhD thesis

Is Decarbonization Achievable? Essays on the Economics of the Energy Transition, 2020

Supervisor: Mouez Fodha; co-supervisor: Olivier Vidal

I study the technical feasibility and the political acceptability of the transition away from fossil fuels. The four chapters collect different papers in environmental economics. The introductory chapter (which has a French version) is original and synthesizes the issues around climate change.

Presentation: french, english.

Master's thesis

International Preferences for Income Distribution, 2016

Supervisors: Thomas Piketty, Michel Forsé

This thesis provides an extensive set of indicators and graphs concerning preferences over distribution of income, using questions from ISSP surveys which ask for perceived and desired wages of several professions in 43 countries. Over the last thirty years, together with the rise of within countries inequalities, people are increasingly in favor of income redistribution : on average, people want a 72% increase on low wages and a 52% decrease on highest incomes. 

Presentation (french), graphics, sources

The Indian welfare system is very costly and inefficient.

Evolution of desired decrease of highest income, data: ISSP

Unpublished

 Basic Income for India: Desirability and Feasibility, 2017

While India spends about 5% of its GDP on social welfare, the bulk of this spending does not reach the poorest. What would be the advantages and drawbacks of unconditional cash transfers as compared to existing schemes? How does empirical evidence support arguments in favor or against a basic income? What is the scope for a basic income, given the financial capacity of the State and the available technology?

Presentation

The Indian welfare system is very costly and inefficient.

An Overview of Participatory Budgeting, 2015

Participatory Budgeting (PB) is a form of direct democracy at the local level, where all citizens state annually prioritized sectors to be financed before allocating investment resources in projects of their choice in those sectors. As lots of studies have been conducted on PB, this paper summarizes the main observations. More precisely, I examine to what extent PB can be an amelioration of local political life, choices, and social conditions.

 

Danser ou Consommer ? Les pauvres aussi peuvent être heureux !, 2013

La zone géographique prédit mieux le bien-être d'un pays que sa richesse ; les latino-américains sont plus heureux que les slaves. Voici les principaux résultats de ce travail, à l'occasion duquel plusieurs indicateurs de bien-être d'un pays ont été définis à partir des données du World Values Survey.

Version grand public, présentation, codes et données

Légende : Proportion de gens se déclarant très heureux (le max de 4 valeurs) suivant le pays.

 Proportion de gens se déclarant très heureux (le maximum d'une échelle à quatre valeurs).

Work on hibernation

Drafts or data available upon request

Accounting For Damages From Sea-Level Rise in IAMs

French Preferences for International Redistribution

Consistent Democratic Program and Budget

Optimal Tax With Keynesian Multiplier

Survey on Social Choice Theorists about the Best Voting Systems, with Jean-François Laslier

Introducing Habit Formation in DICE, with Mohammad Khabbazan