Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Variational principles in set optimization with domination structures and application to changing jobsJournal articleTruong Quang Bao et Antoine Soubeyran, Journal of Applied and Numerical Optimization, Volume 1, Issue 3, pp. 217-241, 2019

This paper is devoted to new versions of Ekeland’s variational principle in set optimization with domination structure, where set optimization is an extension of vector optimization from vector-valued functions to set-valued maps using Kuroiwa’s set-less relations to compare one entire image set with another whole image set, and where domination structure is an extension of ordering cone in vector optimization; it assigns each element of the image space to its own domination set. We use Gerstewitz’s nonlinear scalarization function to convert a set-valued map into an extended real-valued function and the idea of the proof of Dancs-Hegedüs-Medvegyev’s fixed-point theorem. Our setting is applicable to dynamic processes of changing jobs in which the cost function does not satisfy the symmetry axiom of metrics and the class of set-valued maps acting from a quasimetric space into a real linear space. The obtained result is new even in simpler settings.

The Labor Share in the Long Term: A Decline?Journal articleGilbert Cette, Lorraine Koehl et Thomas Philippon, Economie et Statistique / Economics and Statistics, Issue 510-511-512, pp. 35-51, 2019

We challenge the accepted wisdom of a global secular decline in the labor share. A simple theoretical model is proposed to highlight the main factors of change in the labor share. We document three issues in the existing literature: (i) starting periods for the empirical analysis; (ii) accounting for self employment; and (iii) accounting for residential real estate income. An empirical analysis is carried out since the post war period for France and the United States, and since the 1990s for ten developed countries and on a six country “euro area”. How the three questions above are addressed is crucial to the diagnosis. When the biases that may arise with the three issues mentioned above are eliminated, the labor share in the market sector does not show a general downward or upward trend. The choice of period has a huge impact, as does the treatment of real estate services, whose inclusion or not in the value added can result in significantly different trends.

Cross-sectoral pollution externalities and multiple equilibriaJournal articleLarry Karp et Thierry Paul, Environment and Development Economics, Volume 24, Issue 6, pp. 624-642, 2019

In familiar models, a decrease in the friction facing mobile factors (e.g., lowering their adjustment costs) increases a coordination problem, leading to more circumstances where there are multiple equilibria. We show that a decrease in friction can decrease coordination problems when a production externality arises from a changing stock, e.g. of pollution or knowledge. In general, the relation between the amount of friction that mobile factors face and the likelihood of multiple equilibria is non-monotonic.

On Outsourced Abatement Services: Market Power and Efficient RegulationJournal articleDamien Sans, Sonia Schwartz et Hubert Stahn, Annals of Economics and Statistics, Issue 136, pp. 55-78, 2019

In this paper, we consider competitive polluting firms that outsource their abatement activity to an upstream imperfect competitive eco-industry to comply with environmental regulation. In this case, we show that an usual environmental policy based on a Pigouvian tax or a pollution permit market reaches the first-best outcome. The main intuition is based on the idea that purchasing pollution reduction services instead of pollution abatement inputs modifies for each potential tax rate (or out of the equilibrium permit price) the nature of the arbitrage between pollution and abatement. This induces a demand for abatement services which is, at least partially, strongly elastic and therefore strongly reduces upstream market power. This argument is first illustrated with an upstream monopoly selling eco-services to a representative polluting firm under a usual Pigouvian tax. We then progressively extend the result to permit markets, heterogeneous downstream polluters and heterogeneous upstream Cournot competitors.

The determination of public tuition fees in a mixed education system: A majority voting modelJournal articleHejer Lasram et Didier Laussel, Journal of Public Economic Theory, Volume 21, Issue 6, pp. 1056-1073, 2019

We study the determination of public tuition fees through majority voting in a vertical differentiation model where agents' returns on educational investment differ and public and private universities coexist and compete in tuition fees. The private university offers higher educational quality than its competitor, incurring higher unit cost per trained student. The tuition fee for the state university is fixed by majority voting while that for the private follows from profit maximization. Then agents choose to train at the public university or the private one or to remain uneducated. The tax per head adjusts in order to balance the state budget. Because there is a private alternative, preferences for education are not single-peaked and no single-crossing condition holds. An equilibrium is shown to exist, which is one of three types: high tuition fee (the “ends” are a majority), low tuition fee (the “middle” is a majority), or mixed (votes tie). The cost structure determines which equilibrium obtains. The equilibrium tuition is either greater (majority at the ends) or smaller (majority at the middle) than the optimal one.

Job protection, housing market regulation, and the youthJournal articleAntoine Bonleu, Bruno Decreuse et Tanguy van Ypersele, Journal of Public Economic Theory, Volume 21, Issue 6, pp. 1017-1036, 2019

Young Europeans experience high unemployment rates, job instability, and late emancipation. Meanwhile, they do not support reforms weakening protection on long-term contracts. In this paper, we suggest a possible rationale for such reform distaste. When the rental market is strongly regulated, landlords screen applicants with regard to their ability to pay the rent. Protecting regular jobs offers a second-best technology to sort workers, thereby increasing the rental market size. We provide a model where nonemployed workers demand protected jobs despite unemployment and the share of short-term jobs increases, whereas the individual risk of dismissal is unaffected. Our theory can be extended to alternative risks and markets involving correlated risks and commitment under imperfect information.

Banking stability, natural disasters, and state fragility: Panel VAR evidence from developing countriesJournal articlePedro H. Albuquerque et Wassim Rajhi, Research in International Business and Finance, Volume 50, Issue C, pp. 430-443, 2019

Panel VAR methodology is used in this study to empirically evaluate the effects of natural disasters and state fragility on economic and financial dimensions in developing countries such as GDP per capita, banking and financial system deposits, banks’ Z-scores, and non-performing loans. Results based on three panels of up to 66 countries and 17 years of annual data indicate that natural disasters and state fragility may cause significant economic and financial disruption in low-income and middle-income countries. Shocks from natural disasters seem to be temporary and detrimental only to non-performing loans, while shocks from state fragility appear to be permanent and to create detrimental economic and financial feedback loops.

How to turn crowding-out into crowding-in? An innovative instrument and some law-related examplesJournal articleAntoine Beretti, Charles Figuières et Gilles Grolleau, European Journal of Law and Economics, Volume 48, Issue 3, pp. 417-438, 2019

Using a simple decision-theoretic approach, we formalize how agents with different kinds of intrinsic motivations react to the introduction of monetary incentives. We contend that empirical results supporting the existence of a crowding-out effect under various legal procedures hide a more complex reality, where some individuals contribute thanks to these additional monetary incentives while others reduce their contributions. Our approach allows us to study the theoretical ability of the self selection mechanism (Mellstrom and Johannesson in J Eur Econ Assoc 6:845-863, 2008; Beretti et al. in Kyklos 66(1):63-77, 2013) to reduce the likelihood to backfire against the cause it is meant to promote. This mechanism consists of a monetary payment for the pro-social behavior and it offers agents the choice to either keep the money for themselves or to direct it to a charity. We show that this legal procedure dominates others more classical procedures because it taps wisely into the motivational heterogeneity of individuals. It uses a self-selection mechanism to match adequate monetary incentives with individuals' types regarding intrinsic motivations. It may even turn a situation subject to crowding-out into a crowding-in outcome.

A Lipsetian theory of voluntary power handoverJournal articleRaouf Boucekkine, Paolo G. Piacquadio et Fabien Prieur, Journal of Economic Behavior & Organization, Volume 168, Issue C, pp. 269-291, 2019

We consider an autocracy where the ruling elite control both the resource wealth and education policies. Education prompts economic growth and enriches the budget of the elite. However, education also increases the “awareness of citizens” – capturing their reluctance to accept a dictatorship and their labor market aspirations – and forces the elite to expand redistribution or handover the power. A power handover leads to a more democratic regime, where the elite retains (at least partially) its economic power. This trade-off is the backbone of our Lipsetian theory of voluntary power handover. This theory provides new insights on the positive relationship between economic development, education, and democratization, and on the negative relationship between inequality and democratization. Finally, we revisit the resources-curse hypothesis within our setting.

Demystifying China’s Stock Market: The Hidden Logic behind the PuzzlesBookEric Girardin et Zhenya Liu, Springer Books, 2019-12, Number 978-3-030-17123-0, XXI,125 pages, Springer International Publishing, 2019

Mainstream research has rationalized China’s stock market on the basis of paradigms such as the institutional approach, the efficient market hypothesis, and corporate valuation principles. The deviations from such paradigms have been analyzed as puzzles of China’s stock market. Girardin and Liu explore to what extent, in the perspective of Chinese cultural and historical characteristics, far from being puzzles, these 'deviations’ are rather the symptoms of a consistent strategy for the design, development and regulation of a government-dominated financial system. This book will help investors, observers and researchers understand the hidden logic of the design and functioning of China’s modern stock market, taking a political economy view.