Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Variational Analysis and Variational Rationality in Behavioral Sciences: Stationary TrapsBoris S. Mordukhovich et Antoine Soubeyran, , Elisabeth Köbis et Christiane Tammer (Eds.), 2019-07, pp. 1-29, CRC Press, 2019

This paper concerns applications of variational analysis to some local aspects of behavioral science modeling by developing an effective variational rationality approach to these and related issues. Our main attention is paid to local stationary traps, which reflect such local equilibrium and the like positions in behavioral science models that are not worthwhile to quit. We establish constructive linear optimistic evaluations of local stationary traps by using generalized differential tools of variational analysis that involve subgradients and normals for nonsmooth and nonconvex objects as well as variational and extremal principles.

How Variational Rational Agents Would Play Nash: A Generalized Proximal Alternating Linearized MethodAntoine Soubeyran, João Carlos O. Souza et Joao Xavier Cru Neto, , Elisabeth Köbis et Christiane Tammer (Eds.), 2019-07, pp. 55-89, CRC Press, 2019

This chapter considers potential games, where agents play, each period, Nash worthwhile moves in alternation, such that their unilateral motivation to change rather than to stay, other players being supposed to stay, are high enough with respect to their resistance to change rather than to stay. This defines a generalized proximal alternating linearized algorithm, where resistance to change plays a major role, perturbation terms of alternating proximal algorithms being seen as the disutilities of net costs of moving.

Power-law distribution in the external debt-to-fiscal revenue ratios: Empirical evidence and a theoretical modelGilles Dufrénot et Anne-Charlotte Paret, Journal of Macroeconomics, Volume 60, pp. 341-359, 2019

This paper provides evidence that the external debt-to-fiscal revenue ratio in emerging countries follows a power-law distribution. Such a distribution reflects the fact that external debt distress or debt crises correspond to extreme events that have been found to happen fairly often. We formally test the hypothesis of a power-law, going further than the usual visual inspection of the distribution of the variable of interest on a doubly logarithmic scale. We also show that such a distribution can be derived from a theoretical model in which uncertainty comes from tax evasion and corruption. Using the framework of an optimal stochastic growth model, we model the external debt-to-fiscal revenue ratio as a diffusion process for which the stochastic steady state distribution is derived using the properties of Itô diffusion processes.

Work-Related Outcomes in Self-Employed Cancer Survivors: A European Multi-country StudySteffen Torp, Alain Paraponaris, Elke Van Hoof, Marja-Liisa Lindbohm, Sietske J. Tamminga, Caroline Alleaume, Nick Van Campenhout, Linda Sharp et Angela G. E. M. de Boer, Journal of Occupational Rehabilitation, Volume 29, Issue 2, pp. 361-374, 2019

Purpose To describe: (i) patterns of self-employment and social welfare provisions for self-employed and salaried workers in several European countries; (ii) work-related outcomes after cancer in self-employed people and to compare these with the work-related outcomes of salaried survivors within each sample; and (iii) work-related outcomes for self-employed cancer survivors across countries. Methods Data from 11 samples from seven European countries were included. All samples had cross-sectional survey data on work outcomes in self-employed and salaried cancer survivors who were working at time of diagnosis (n = 22–261 self-employed/101–1871 salaried). The samples included different cancers and assessed different outcomes at different times post-diagnosis. Results Fewer self-employed cancer survivors took time off work due to cancer compared to salaried survivors. More self-employed than salaried survivors worked post-diagnosis in almost all countries. Among those working at the time of survey, self-employed survivors had made a larger reduction in working hours compared to pre-diagnosis, but they still worked more hours per week post-diagnosis than salaried survivors. The self-employed had received less financial compensation when absent from work post-cancer, and more self-employed, than salaried, survivors reported a negative financial change due to the cancer. There were differences between self-employed and salaried survivors in physical job demands, work ability and quality-of-life but the direction and magnitude of the differences differed across countries. Conclusion Despite sample differences, self-employed survivors more often continued working during treatment and had, in general, worse financial outcomes than salaried cancer survivors. Other work-related outcomes differed in different directions across countries.

Impacts of the Québec carbon emissions trading scheme on plant-level performance and employmentJulien Hanoteau et David Talbot, Carbon Management, Volume 10, Issue 3, pp. 287-298, 2019

In 2013, Québec implemented a greenhouse gas (GHG) emissions trading system (QC ETS), despite opposition from industry, which feared loss of competitiveness and warned about job destruction. This article assesses the impact of that carbon regulation on industrial facilities in Québec. Conditional difference-in-differences ordinary least squares regressions show that regulated plants reduced their GHG emissions by about 9.8%, employment by about 6.8% and carbon intensity by about 3.7% more compared to non-regulated plants in the rest of Canada during the period 2013–2015. This suggests that facilities adapted to the new program by improving their technology, but first and foremost by scaling down their activity, which raises questions about the ability of the QC ETS to induce enough environmental investment and innovation in industrial facilities. The results, in terms of employment effects, contrast with the findings of similar studies on the early stages of the European ETS and the British Columbia carbon tax scheme, and this information challenges the initial allocation scheme for permits, in particular, with a view to a green fiscal reform.

Platform competition: Who benefits from multihoming?Paul Belleflamme et Martin Peitz, International Journal of Industrial Organization, Volume 64, pp. 1-26, 2019

Competition between two-sided platforms is shaped by the possibility of multihoming (i.e., some users joining both platforms). If initially both sides singlehome, each platform provides users on one side exclusive access to its users on the other side. If then one side multihomes, platforms compete on the singlehoming side and exert monopoly power on the multihoming side. This paper explores the allocative effects of such a change from single- to multihoming. Our results challenge the conventional wisdom, according to which the possibility of multihoming hurts the side that can multihome, while benefiting the other side. This in not always true, as the opposite may happen or both sides may benefit.

A Tale of Two DiversitiesPierre Courtois, Charles Figuières et Chloe Mulier, Ecological Economics, Volume 159, pp. 133-147, 2019

Efficient biodiversity management strategies aim to allocate conservation efforts so as to maximize diversity in ecological systems. Toward this end, defining a diversity criterion is an important but challenging task, as several different indices can be used as biodiversity measures. This paper elicits and compares two criteria for biodiversity conservation based on indices stemming from different disciplines: Weitzman's index in economics and Rao's index in ecology. These indices use different approaches to combine information about measures of (1) the probability distributions of the species that are present in an ecosystem (i.e. survival probabilities) and (2) the degree of dissimilarity between these species. As an important step toward in situ conservation criteria, we add to these elements information about (3) the ecological interactions that take place between species. Considering a simple three-species ecosystem, we show that criterion choice has palpable policy implications, as it can sometimes lead to divergent management recommendations. We disentangle the roles played by elements (1), (2) and (3) in the ranking of outcomes, which allows us to highlight several specificities of the two criteria. An important result is that, other things being equal, Weitzman's in situ ranking tends to favor robust species that are least concerned with extinction, while Rao's in situ ranking generally gives priority to more vulnerable species that are closer to extinction.

Growth and bubbles: Investing in human capital versus having childrenXavier Raurich et Thomas Seegmuller, Journal of Mathematical Economics, Volume 82, pp. 150-159, 2019

As it is documented, households’ investment in their own education (human capital) is negatively related to the number of children individuals will have and requires some loans to be financed. We show that this contributes to explain episodes of bubbles associated to higher growth rates. This conclusion is obtained in an overlapping generations model where agents choose to invest in their own education and decide their number of children. A bubble is a liquid asset that can be used to finance either education or the cost of rearing children. The time cost of rearing children plays a key role in the analysis. If the time cost per child is sufficiently high, households have only a small number of children. Then, the bubble has a crowding-in effect because it is used to provide loans to finance investments in education. On the contrary, if the time cost per child is low enough, households have a large number of children. Then, the bubble is mainly used to finance the total cost of rearing children and has a crowding-out effect on investment. Therefore, the new mechanism we highlight shows that a bubble enhances growth if the economy is characterized by a high rearing time cost per child.

Financial constraints, institutions, and foreign ownershipRon Alquist, Nicolas Berman, Rahul Mukherjee et Linda L. Tesar, Journal of International Economics, Volume 118, pp. 63-83, 2019

We develop a model of cross-border acquisitions in which the foreign acquirer's ownership choice reflects a trade-off between easing the target's credit constraints and the costs of operating in an environment with weak institutions. Data on domestic and foreign acquisitions in emerging markets over the period 1990–2007 support the model predictions. The share of full foreign acquisitions is higher in sectors more reliant on external finance, in countries with lower financial development, and in countries with higher institutional quality. Sectoral external finance dependence accentuates the effect of country-level financial development and institutional quality. By contrast, the level of foreign ownership in partial acquisitions is insensitive to institutional factors and depends weakly on financial factors.

Philosophie économique. Une introductionGilles Campagnolo et Jean-Sébastien Gharbi, 2019-04, 166 pages, Editions Matériologiques, 2019

Attitude théorique et pratique, la philosophie économique est une démarche intellectuelle qui articule économie et philosophie. Mais comment la définir ? Et d’où vient l’intérêt grandissant que l’on constate depuis vingt ans ? Quelles ressources pluralistes mobilise-t-elle et comment s’est-elle constituée ? Quels rapports entretient-elle avec la théorie économique, l’histoire de la pensée et les philosophies morale et politique ? À ces questions, notamment, et en s’appuyant sur l’ouvrage collectif Philosophie économique. Un état des lieux (Éditions Matériologiques, 2017, 648 pages), cette introduction donne des réponses fondamentales, claires et précises.