"Democratic Social Cost of Carbon"
"Climate change damage through extreme events"
"A Systemic Perspective on the Challenge of Climate Change Mitigation"
This paper examines the key barriers to climate change mitigation and their interconnections, offering a systemic perspective. The first requirement is the implementation of stronger public policies, which depends on the second: establishing more robust international agreements. These, in turn, rely on a third and more fundamental condition - a societal shift toward valuing the long term. Without this deep transformation, efforts to secure effective international agreements and implement strong public policies are destined to fail.
"Disagreement Aversion" (with Bommier, A., Fabre, A., and Heyen, D.) Journal of Economic Theory - R&R
Experts often disagree. A decision-maker may be averse to such expert disagreement. Existing models of aversion to expert disagreement rest on ambiguity-averse preferences adopting a unanimity principle: If all experts consider one choice 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 to distinguish spurious from genuine unanimity and develop a model that can capture disagreement aversion in our sense. The central element of our model is the cautious aggregation of experts’ beliefs.
"Are Current Generations' Preferences the Primary Barrier to Climate Change Mitigation?" Oxford Open Climate Change (2025) [WP]
This paper argues that the climate economics literature often overlooks the role of generational self-interest in hindering ambitious climate change mitigation. A deeper examination of this self-interest could improve public awareness of their role in current low levels of mitigation and guide future research towards critical questions needed to overcome the generational barrier to significant climate action.
"Democratic Climate Policies with Overlapping Generations" Environmental and Resource Economics (2024) - EAERE Award for Outstanding Publication in ERE - [WP]
An extensive climate policy literature provides various recommendations for mitigating climate change, but these recommendations are not supported democratically, since the models employed consider either infinitely-lived individuals or normative social objectives (or both). In contrast, the present paper provides policy recommendations capable of incorporating democratic processes. I develop an overlapping generation model with political process micro-foundations and show how democratic climate policies are interconnected with other democratic policies. Time inconsistent social objectives combined with commitment issues lead to an inefficient tax on capital accumulation and a climate policy below the efficient level; while suppressing the tax on capital accumulation generates a climate policy even further below the efficient level. I derive a novel politico-economic Keynes-Ramsey rule for the market interest rate, which is useful for calculating the climate policy level. I show that individual pure time preference, individual altruism toward descendants, and young generation political power are key determinants of democratic climate policy ambition.
"Catastrophe Insurance and Solvency Regulation" (with Louaas, A.) Geneva Risk and Insurance Review (2024) [WP]
Solvency regulation can prevent insurers from making decisions that are detrimental to policyholders. However, it can also discourage the purchase of insurance for catastrophic risks by causing prohibitive insurance loading due to high reinsurance coverage constraints. This paper examines this delicate trade-off. We show that a solvency regulation allowing some level of insurer default in catastrophic states can be a first-best policy. The default rate of this first-best policy varies depending on the risk line and market conditions. Our numerical simulations indicate that it is possible to closely approximate the first-best policy by implementing a straightforward solvency regulation, considering insurers’ Expected Shortfall and Value at Risk, the reinsurance loading, and policyholders’ risk aversion. Therefore, reforming current solvency regulations in this direction could improve policyholders’ welfare.
"Altruistic Foreign Aid and Climate Change Mitigation" (with Bommier, A., Goerger, A., and Nicolaï, J.P. ) Environmental and Resource Economics (2023) [WP]
This paper considers one altruistic developed country and several heterogeneous developing countries. We demonstrate that the lack of coordination between countries in tackling climate change finds an optimal solution if developing countries can expect to receive development aid transfers from the developed country. The mechanism requires a sufficiently high level of altruism and specific timing, but a global coalition is not necessary. We also show that the developed country may democratically assign a delegate who is more altruistic than its median voter in order to benefit from the efficiency gain generated by positive development aid transfers.
"Risk Allocation and Financial Intermediation" Mathematical Social Sciences (2022) [WP]
The classic Arrow-Debreu framework requires a very large number of specific securities to reach Pareto optimality. The present paper shows that financial intermediation can play an important role in maintaining a more parsimonious market framework while still obtaining Pareto optimality. In the framework developed, the aggregate risk components of individual risks are exchanged through a highly reduced set of nonspecific securities, while the idiosyncratic risk components are insured through financial intermediation. Reaching Pareto optimality does not rest on a Law of Large Numbers approximation. The role of financial intermediation is complementary to the role of security derivatives and dynamic trading.
"Prevention and Insurance in Cities Exposed to Natural Disaster Risks" Annals of Economics and Statistics (2020) [WP]
Prevention and insurance are studied in an urban model with spatial heterogeneity due not only to commuting transport costs but also to natural disaster risks. Costly insurance and charity donation both lead to low insurance purchase. While the former leads to high prevention, the latter leads to low prevention. In the presence of charity, implementing insurance or building resilience subsidies may lead to even less prevention through higher development of risky areas. In all events, a public insurance policy with actuarially fair rates accounting for resilience investment and with full coverage requirements, along with lump-sum transfers, leads to Pareto improvement.
"Impact of Realistic Hourly Emissions Profiles on Air Pollutants Concentrations Modelled with CHIMERE" (with Menut, L., Bessagnet, B., Khvorostiyanov, D., and Ung, A.) Atmospheric Environment (2012)
Regional chemistry-transport models study atmospheric composition for analysis, scenarios, trends, and forecasts. Modeled concentrations rely on inputs like annual emissions of NOx,, VOCs, and particulate matter, which are distributed spatially and temporally. Modelers estimate pollutant fluxes and time resolution is critical. Standard approaches use averaged factors to convert annual data into hourly emissions, affecting accuracy. Using the CHIMERE model, this study improves traffic emission flux calculations by using hourly roadside NO2 measurements as proxies. Results reveal differing diurnal emission patterns across countries and suggest adopting new hourly emission factors. For Europe in the summer of 2007, nighttime pollutant concentrations better match measurements, though daily ozone peaks remain unaffected.
"Prevention and Insurance of Natural Disasters" Ph.D. thesis (2016)
"Revue Critique des Etudes Evaluant l’Effet des Changements d’Affectation des Sols sur les Bilans Environnementaux des Biocarburants" (with De Cara, S., Grateau, R., Levert, F., Quemener, J., and Vermont, B.) ADEME Technical Paper (2012)
"La Maîtrise des Rejets Urbains de Temps de Pluie sur le Bassin Seine-Normandie. Quels Retours d’Expérience sur les Bassins d’Orage ?" (with Aires, N., and Jestin, E.) Techniques Sciences Méthodes (2009)