Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Contracting Under Unverifiable Monetary CostsJournal articleNicolas Quérou, Antoine Soubeyran et Raphaël Soubeyran, Journal of Economics and Management Strategy, Forthcoming

We consider a contracting relationship where the agent's effort induces monetary costs, and limits on the agent's resource restrict his capability to exert effort. We show that, the principal finds it best to offer a sharing contract while providing the agent with an up-front financial transfer only when the monetary cost is neither too low nor too high. Thus, unlike in the limited liability literature, the principal might find it optimal to fund the agent. Moreover, both incentives and the amount of funding are non-monotonic functions of the monetary cost. These results suggest that an increase in the interest rate may affect the form of contracts differently , depending on the initial level of the former. Using the analysis, we provide and discuss several predictions and policy implications.

An evolutionary finance model with short selling and endogenous asset supplyJournal articleRabah Amir, Sergei Belkov, Igor V. Evstigneev et Thorsten Hens, Economic Theory, Forthcoming

Evolutionary finance focuses on questions of “survival and extinction” of investment strategies (portfolio rules) in the market selection process. It analyzes stochastic dynamics of financial markets in which asset prices are determined endogenously by a short-run equilibrium between supply and demand. Equilibrium is formed in each time period in the course of interaction of portfolio rules of competing market participants. A comprehensive theory of evolutionary dynamics of this kind has been developed for models in which short selling is not allowed and asset supply is exogenous. The present paper extends the theory to a class of models with short selling and endogenous asset supply.

Altruism and Risk Sharing in NetworksJournal articleRenaud Bourlès, Yann Bramoullé et Eduardo Perez-Richet, Journal of the European Economic Association, Forthcoming

We provide the first analysis of the risk sharing implications of altruism networks. Agents are embedded in a fixed network and care about each other. We explore whether altruistic transfers help smooth consumption and how this depends on the shape of the network. We find that altruism networks have a first-order impact on risk. Altruistic transfers generate efficient insurance when the network of perfect altruistic ties is strongly connected. We uncover two specific empirical implications of altruism networks. First, bridges can generate good overall risk sharing and, more generally, the quality of informal insurance depends on the average path length of the network. Second, large shocks are well-insured by connected altruism networks. By contrast, large shocks tend to be badly insured in models of informal insurance with frictions. We characterize what happens for shocks that leave the structure of giving relationships unchanged. We further explore the relationship between consumption variance and centrality, correlation in consumption streams across agents and the impact of adding links.

Learning with minimal information in continuous gamesJournal articleSebastian Bervoets, Mario Bravo et Mathieu Faure, Theoretical Economics, Forthcoming

While payoff-based learning models are almost exclusively devised for finite action games, where players can test every action, it is harder to design such learning processes for continuous games. We construct a stochastic learning rule, designed for games with continuous action sets, which requires no sophistication from the players and is simple to implement: players update their actions according to variations in own payoff between current and previous action. We then analyze its behavior in several classes of continuous games and show that convergence to a stable Nash equilibrium is guaranteed in all games with strategic complements as well as in concave games, while convergence to Nash occurs in all locally ordinal potential games as soon as Nash equilibria are isolated.

Egalitarian redistribution in the era of hyper-globalizationJournal articleGianluca Grimalda, Alain Trannoy, Fernando Filgueira et Karl Ove Moene, Review of Social Economy, pp. 1-34, Forthcoming

Two traditional theorems of welfare economics posit a trade-off between a government redistribution targets and efficiency. We propose a third ‘claim’ of welfare economics, stating that in closed economies the actual efficiency costs associated with redistribution are small. We then examine the claim in the current phase of ‘hyper-globalization’. On the one hand, a race-to-the-bottom in taxation restricts the capacity to tax high-earners and the associated brain drain may affect a country’s long-run growth. On the other hand, demand for social insurance should be particularly high in an open economy, especially with advancing digitalization. Xenophobic sentiments may, however, offset this demand. We also discuss the impact of globalization on wage equalization and productive efficiency. We conclude against the idea that the welfare state is intrinsically unable to carry out its redistributive function in an era of globalization. However, its strategies and tools of intervention must be rethought.

The long-lasting effects of family and childhood on adult wellbeing: Evidence from British cohort dataJournal articleSarah Flèche, Warn N. Lekfuangfu et Andrew E. Clark, Journal of Economic Behavior & Organization, Forthcoming

To what extent do childhood experiences continue to affect adult wellbeing over the life course? Previous work on this link has been carried out either at one particular adult age or for some average over adulthood. We here use two British birth-cohort datasets (the 1958 NCDS and the 1970 BCS) to map out the time profile of the effect of childhood experiences on adult outcomes, including life satisfaction. We find that the effects of many aspects of childhood do not fade away over time but are rather remarkably stable. In both birth-cohorts, child non-cognitive skills are the strongest predictors of adult life satisfaction at all ages. Of these, emotional health is the strongest. Childhood cognitive performance is more important than good conduct in explaining adult life satisfaction in the earlier NCDS cohort, whereas this ranking is inverted in the more recent BCS.

Convergence of GDP per capita in advanced countries over the twentieth centuryJournal articleAntonin Bergeaud, Gilbert Cette et Rémy Lecat, Empirical Economics, Forthcoming

This study compares GDP per capita levels and growth rates across 17 advanced economies over the period 1890–2013 using an accounting breakdown and runs Phillips and Sul (Econometrica 75(6):1771–1855, 2007) convergence tests. An overall convergence process has been at work among advanced economies, mainly after WWII, driven mostly by capital intensity and then TFP, while trends in hours worked and employment rates are disparate. However, this convergence process came to a halt during technology shocks, during the two world wars and since the 1990s, with the convergence of advanced economies stopping far from the level of US GDP per capita.

Modeling the impact of product quality on dynamic pricing and advertising policiesJournal articleRégis Y. Chenavaz, Gustav Feichtinger, Richard F. Hartl et Peter M. Kort, European Journal of Operational Research, Forthcoming

The marketing-mix of price–quality and advertising–quality relationship is well studied. Less understood is the price–advertising–quality relationship. This article fills the gap, investigating the interplay between price, advertising, and quality in an optimal control model. Our results generalize the condition of Dorfman–Steiner in a dynamic context. Also, they point to the impact of greater product quality on the dynamic policies of pricing and advertising. Furthermore, a phase diagram analysis shows that quality develops monotonically in time and converges to a unique steady state. We also show that quality investment could either decrease or increase over time but this depends on its effectiveness. Our results spot the profitable opportunities of a firm managing a more complex marketing-mix.

Time-varying consumption tax, productive government spending, and aggregate instabilityJournal articleMauro Bambi et Alain Venditti, International Journal of Economic Theory, Volume n/a, Issue n/a, Forthcoming

In this paper we investigate if government balanced-budget rules together with endogenous taxation may lead to aggregate instability in an endogenous growth framework. After highlighting the differences with the exogenous growth framework, we prove that under counter-cyclical consumption taxes, while there exists a unique balanced growth path, sunspot equilibria based on self-fulfilling expectations occur through a form of global indeterminacy. In addition, we argue that this result is empirically plausible for a large set of OECD countries and that it may also emerge with endogenous income taxes.

Complementary Monopolies with asymmetric informationJournal articleDidier Laussel et Joana Resende, Economic Theory, Forthcoming

We investigate how asymmetric information on final demand affects strategic interaction between a downstream monopolist and a set of upstream monopolists, who independently produce complementary inputs. We study an intrinsic private common agency game in which each supplier i independently proposes a pricing schedule contract to the assembler, specifying the supplier’s payment as a function of the assembler’s purchase of input i. We provide a necessary and sufficient equilibrium condition. A lot of equilibria satisfy this condition but there is a unique Pareto-undominated Nash equilibrium from the suppliers’ point of view. In this equilibrium, there are unavoidable efficiency losses due to excessively low sales of the good. However, suppliers may be able to limit these distortions by implicitly coordinating on an equilibrium with a rigid (positive) output in bad demand circumstances.