Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Counting the missing poor in pre-industrial societiesJournal articleMathieu Lefebvre, Cliometrica, Forthcoming

Under income-differentiated mortality, poverty measures suffer from a selection bias: they do not count the missing poor (i.e., persons who would have been counted as poor provided they did not die prematurely). The Pre-Industrial period being characterized by an evolutionary advantage (i.e., a higher number of surviving children per household) of the non-poor over the poor, one may expect that the missing poor bias is substantial during that period. This paper quantifies the missing poor bias in Pre-Industrial societies, by computing the hypothetical headcount poverty rates that would have prevailed provided the non-poor did not benefit from an evolutionary advantage over the poor. Using data on Pre-Industrial England and France, we show that the sign and size of the missing poor bias are sensitive to the degree of downward social mobility.

The role of investor behavior in emerging stock markets: Evidence from VietnamJournal articleThi Nha Truc Phan, Philippe Bertrand, Hong Hai Phan et Xuan Vinh Vo, The Quarterly Review of Economics and Finance, Forthcoming

Exloring the role of different types of investors on stock market is crticial since different types of investors react and behave differently when making investment decision. The role of investor behavior is a very important issue in an immature stock market like Vietnam stock market because the market is characterized by a large number of individual investors and low reporting standard. Institutional and foreign investors however play an influential role due to their large exposure and strong investment expertise. Clearly, examining the role of investor behavior and its impact on the stock market in Vietnam is an important topic in finance. A significant body of empirical research has shown that investor behavior is an essential factor to explain stock price that the classical financial theory cannot explain. This research examines the role of investor behavior in stock market by examining the relationship between investor behavior and stock return using the Vietnamese stock exchange data. We create a sentiment index using the principal components analysis (PCA). Consistent with the sentiment and stock return literature, the research shows a negative contemporaneous relationship between investor sentiment and market return.

Bread and Social Justice: Measurement of Social Welfare and Inequality Using AnthropometricsJournal articleMohammad Abu-Zaineh et Ramses H. Abul Naga, Review of Income and Wealth, Volume n/a, Issue n/a, Forthcoming

We address the question of the measurement of health achievement and inequality in the context of variables exhibiting an inverted-U relation with health and well-being. The chosen approach is to measure separately achievement and inequality in the health increasing range of the variable, from a lower survival bound a to an optimum value m, and in the health decreasing range from m to an upper survival bound b. Because in the health decreasing range, the equally distributed equivalent value associated with a distribution is decreasing in progressive transfers, the paper introduces appropriate relative and absolute achievement and inequality indices to be used for variables exhibiting a negative association with well-being. We then discuss questions pertaining to consistent measurement across health attainments and shortfalls, as well as the ordering of distributions exhibiting an inverted-U relation with well-being. An illustration of the methodology is provided using a group of five Arab countries.

Enquête sur les libertés et l’égalité : Tome 1 : Origines et fondements - Volume 2 : Economie, et métaphysiqueBookPhilippe Grill, E-conomiques, Number 2, Forthcoming

Le projet de Philippe Grill est d’enquêter sur les origines et les fondements des doctrines et théories relatives aux libertés et à l’égalité. Son approche est proprement philosophico-économique, au sens où elle s’appuie sur l’une et l’autre discipline. Cette exploration conceptuelle des théories économiques et philosophiques, des hypothèses qui les fondent, des notions qui les irriguent, ou encore des masses de données empiriques aux interprétations multiples, voire contradictoires, se révèle cruciale car c’est à partir de ces doctrines et théories que sont conçues et promues les organisations sociales et les politiques publiques qui déterminent « dans quel monde on vit », en décrétant le possible et l’impossible en ces domaines. L’ouvrage contribue ainsi pleinement aux débats actuels d’éthique sociale en fournissant les moyens de définir ce que pourrait être une organisation sociale « humaniste ».
En effet, si l’on veut changer le monde, il faut le comprendre… Sereinement, pédagogiquement, c’est notamment à cette compré­hen­sion maximale que nous invite Philippe Grill. La somme encyclopédique qu’il nous propose déploie le panorama d’une philosophie économique où sont convoqués les savoirs contemporains issus de nombreuses disciplines (outre les sciences économiques bien sûr, les autres sciences sociales, la logique, l’épistémologie, les sciences cognitives, les neurosciences, la biologie de l’évolution, etc., ainsi que les engagements ontologiques des nombreux penseurs que l’ouvrage étudie). Ici, point de simple juxtaposition de disciplines, mais une architecture des connaissances qui veut montrer que les conceptions idoines sont nécessairement connexes si l’on entend démêler l’écheveau d’un homo œconomicus authentique, renversant le modèle factice que rabâchent les propagandistes de vulgates économiques outrancièrement simplistes et irréalistes. Ainsi, ce livre est un puissant levier de ce mouvement salutaire. Moins

Pollution in a globalized world: Are debt transfers among countries a solution?Journal articleMarion Davin, Mouez Fodha et Thomas Seegmuller, International Journal of Economic Theory, Volume n/a, Issue n/a, Forthcoming

We analyze the effects of a debt relief, that is, a decrease in public debt of a low-income country financed by a high-income country, on environmental quality. Under perfect mobility of assets, the debt relief increases the overall capital stock, and environmental quality when public abatements are sufficiently efficient. Welfare in both countries can also improve. Under a weak mobility of assets, capital does no more increase in the richest country, but environmental quality can improve. This comes from a crowding-out effect of debt in the high-income country, which does no more take place when the mobility of assets is significant.

Environment, public debt, and epidemicsJournal articleMarion Davin, Mouez Fodha et Thomas Seegmuller, Journal of Public Economic Theory, Volume n/a, Issue n/a, Forthcoming

We study whether fiscal policies, especially public debt, can help to curb the macroeconomic and health consequences of epidemics. Our approach is based on three main features: we introduce the dynamics of epidemics in an overlapping generations model to take into account that old people are more vulnerable; people are more easily infected when pollution is high; public spending in health care and public debt can be used to tackle the effects of epidemics. We show that fiscal policies can promote convergence to a stable disease-free steady state. When public policies are not able to permanently eradicate the epidemic, public debt, and income transfers could reduce the number of infected people and increase capital and GDP per capita. As a prerequisite, pollution intensity should not be too high. Finally, we define a household subsidy policy that eliminates income and welfare inequalities between healthy and infected individuals.

Bunching in rank-dependent optimal income tax schedulesJournal articleLaurent Simula et Alain Trannoy, Social Choice and Welfare, Forthcoming

Considering optimal non-linear income tax problems when the social welfare function only depends on ranks as in Yaari (Econometrica 55(1):95–115, 1987) and weights agreeing with the Lorenz quasi-ordering, we extend the analysis of Simula and Trannoy (Am Econ J Econ Policy, 2021) in two directions. First, we establish conditions under which bunching does not occur in the social optimum. We find a sufficient condition on individual preferences, which appears as a reinforcement of the Spence-Mirrlees condition. In particular, the marginal dis-utility of gross income should be convex, but less convex the higher the productivity. We also show that, for all productivity distributions with a log-concave survival function, bunching is precluded under the maximin, Gini, and “illfare-ranked single-series Ginis”. Second, we turn to a discrete population setting, and provide an “ABC” formula for optimal marginal tax rates, which is related to those for a continuum of types found in Simula and Trannoy (2021), but remain essentially distinct.

Robust Ekeland variational principles. Application to the formation and stability of partnershipsJournal articleMajid Fakhar, Mohammadreza Khodakhah, Antoine Soubeyran et Jafar Zafarani, Optimization, Forthcoming

This paper has two parts. The mathematical part provides generalized versions of the robust Ekeland variational principle in terms of set-valued EVP with variable preferences, uncertain parameters and changing weights given to vectorial perturbation functions. The behavioural part that motivates our findings models the formation and stability of a partnership in a changing, uncertain and complex environment in the context of the variational rationality approach of stop, continue and go human dynamics. Our generalizations allow us to consider two very important psychological effects relative to ego depletion and goal gradient hypothesis.

The Bayesian approach to poverty measurementBook chapterMichel Lubrano et Zhou Xun, In: Handbook of Research on Measuring Poverty and Deprivation, J. Silber (Eds.), Edward Elgar Publishing, Forthcoming

In this chapter, we revisit the origins and genesis of the french school of proximity and its evolution trough time, in order to better understand how and why the small group of researchers who were the driving force of this new way of thinking were quickly able to get a real legitimacy and effective recognition. First of all, it was clear that the role of space in economic dynamics was too often the subject of confusion and abusive assertions. Asking this question in terms of coordination made it possible to consider non-spatial factors in the analysis. The notion of proximity as a polysemic concept therefore opened the way to understanding how space matters or not, together with these other factors thus a renewed approach of questions related to space and territories. But, even starting from issues of economic nature, such an approach could not remain limited to its economic dimension, the questions of coordination involving social individuals, located in geographical space but also embedded in bundles of relationships and in institutions. Thus, it had to broaden very quickly to other disciplines in social sciences which largely contributed to consolidate the bases of what became a multidisciplinary approach and to develop theoretical as well as empirical tools.

Enquête sur les libertés et l’égalité : Tome 2 : Théories et prolongements - Volume 3BookPhilippe Grill, E-conomiques, 569 pages, Forthcoming

Le projet de Philippe Grill est d’enquêter sur les origines et les fondements des doctrines et théories relatives aux libertés et à l’égalité. Son approche est proprement philosophico-économique, au sens où elle s’appuie sur l’une et l’autre discipline. Cette exploration conceptuelle des théories économiques et philosophiques, des hypothèses qui les fondent, des notions qui les irriguent, ou encore des masses de données empiriques aux interprétations multiples, voire contradictoires, se révèle cruciale car c’est à partir de ces doctrines et théories que sont conçues et promues les organisations sociales et les politiques publiques qui déterminent « dans quel monde on vit », en décrétant le possible et l’impossible en ces domaines. L’ouvrage contribue ainsi pleinement aux débats actuels d’éthique sociale en fournissant les moyens de définir ce que pourrait être une organisation sociale « humaniste ».
En effet, si l’on veut changer le monde, il faut le comprendre… Sereinement, pédagogiquement, c’est notamment à cette compré­hen­sion maximale que nous invite Philippe Grill. La somme encyclopédique qu’il nous propose déploie le panorama d’une philosophie économique où sont convoqués les savoirs contemporains issus de nombreuses disciplines (outre les sciences économiques bien sûr, les autres sciences sociales, la logique, l’épistémologie, les sciences cognitives, les neurosciences, la biologie de l’évolution, etc., ainsi que les engagements ontologiques des nombreux penseurs que l’ouvrage étudie). Ici, point de simple juxtaposition de disciplines, mais une architecture des connaissances qui veut montrer que les conceptions idoines sont nécessairement connexes si l’on entend démêler l’écheveau d’un homo œconomicus authentique, renversant le modèle factice que rabâchent les propagandistes de vulgates économiques outrancièrement simplistes et irréalistes. Ainsi, ce livre est un puissant levier de ce mouvement salutaire.