Publications

Abstract OECD countries have experienced a large increase in top wage inequality. Atkinson (2008) attributes this phenomena to the superstar theory leading to a Pareto tail in the wage distribution with a low Pareto coefficient. Do we observe a similar phenomena for academic wages? We examine wage formation in a public US university using for each academic rank a hybrid mixture formed by a lognormal distribution for regular wages and a Pareto distribution for top wages, using a Bayesian approach. The presence of superstars wages would imply a higher dispersion in the Pareto tail than in the lognormal body. We concluded that academic wages are formed in a different way than other top wages. There is an effort to propose competitive wages to some young Assistant Professors. But when climbing up the wage ladder, we found a phenomenon of wage compression which is just the contrary of a superstar phenomenon.
Keywords Wage compression, Wage formation, Tournaments theory, Hybrid mixtures, Bayesian inference, Academic market, Superstar wages
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Abstract The purpose of this paper is twofold. First, we examine convergence properties of an inexact proximal point method with a quasi distance as a regularization term in order to find a critical point (in the sense of Toland) of a DC function (difference of two convex functions). Global convergence of the sequence and some convergence rates are obtained with additional assumptions. Second, as an application and its inspiration, we study in a dynamic setting, the very important and difficult problem of the limit of the firm and the time it takes to reach it (maturation time), when increasing returns matter in the short run. Both the formalization of the critical size of the firm in term of a recent variational rationality approach of human dynamics and the speed of convergence results are new in Behavioral Sciences.
Keywords Variational rationality, Proximal point method, Kurdyka–Łojasiewicz inequality, DC function, Limit of the firm
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Abstract This paper investigates the link between parental separation and children's achievement in adulthood. Using a French dataset on “Education-Training-Employment”, I first estimate a random effects model and then examine the differences in age at divorce for children within the same family, to control for divorced family selection. Three outcomes are analysed: number of years of schooling, earnings-weighted education and social position. Using a random effects model, parental separation is linked to poorer educational attainment for their children, from 32% to 12% of a standard deviation lower where the number of years of education is concerned, and from 30% to 8% of a standard deviation lower where the earnings-weighted education is concerned. This effect varies with age: least affected are the 16 to 18-year-olds, and most affected are the youngest. Where social position is concerned, effects are weaker, but remain negative. Accounting for the family fixed effect yields somewhat weaker estimated effects for the youngest, but results remain similar. Parental separation is more detrimental to boys' education under both models, but conducting a F-test, we only reject the nul hypothesis for earnings-weighted education where family fixed effect is accounted for. In results from both models, teenagers who experience a parental separation are less affected if born after 1970, but differences are not statistically different from zero where the family fixed effect is accounted for.
Keywords Marital Dissolution, Family Structure, Divorce, Education, Labour Market Outcomes
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Abstract We introduce an approach based on functional data analysis to identify patterns of malaria incidence to guide effective targeting of malaria control in a seasonal transmission area. Using functional data method, a smooth function (functional data or curve) was fitted from the time series of observed malaria incidence for each of 575 villages in west-central Senegal from 2008 to 2012. These 575 smooth functions were classified using hierarchical clustering (Ward’s method), and several different dissimilarity measures. Validity indices were used to determine the number of distinct temporal patterns of malaria incidence. Epidemiological indicators characterizing the resulting malaria incidence patterns were determined from the velocity and acceleration of their incidences over time. We identified three distinct patterns of malaria incidence: high-, intermediate-, and low-incidence patterns in respectively 2% (12/575), 17% (97/575), and 81% (466/575) of villages. Epidemiological indicators characterizing the fluctuations in malaria incidence showed that seasonal outbreaks started later, and ended earlier, in the low-incidence pattern. Functional data analysis can be used to identify patterns of malaria incidence, by considering their temporal dynamics. Epidemiological indicators derived from their velocities and accelerations, may guide to target control measures according to patterns.
Keywords Malaria dynamic, Malaria patterns, Time series clustering, Functional data analysis
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Abstract Although it is widely acknowledged that non-cognitive skills matter for adult outcomes, little is known about the role played by family environment in the formation of these skills. We use a longitudinal survey of children born in the UK in 2000–2001, the Millennium Cohort Study by the Centre for Longitudinal Studies, to estimate the effect of family size on socio-emotional skills, measured by the Strengths and Difficulties Questionnaire. To account for the endogeneity of fertility decisions, we use a well-known instrumental approach that exploits parents’ preference for children’s gender diversity. We show that the birth of a third child negatively affects the socio-emotional skills of the first two children in a persistent manner. However, we show that this negative effect is entirely driven by girls. We provide evidence that this gender effect is partly driven by an unequal response of parents’ time investment in favour of boys and, to a lesser extent, by an unequal demand for household chores.
Keywords Non-cognitive skills, Family size, Birth order, Child development
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Abstract This chapter discusses the potential impacts of the spread of COVID-19, and the restriction policies that it has triggered in many countries, on conflict incidence worldwide. Based on anecdotal evidence and recent research, we argue that imposing nation-wide shutdown policies diminishes conflict incidence on average, but that this conflict reduction may be short-lived and highly heterogeneous across countries. In particular, conflict does not appear to decline in poor, fractionalised countries. Evidence points to two potential ways in which COVID-related restriction policies may increase conflict: losses in income and magnified ethnic and religious tensions leading to scapegoating of minorities.
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Abstract In this paper, we develop a unified spatial model of turnout and voting behaviors in which citizens can identify with one or two parties. We show the existence of a conflicted voter's curse: If there is no position that reconciles the ideological views of both parties, it is always rational for citizens that identify with two parties to abstain even if they are a majority. In a two-candidate electoral competition, the conflicted voter's curse implies that candidates converge to the center of the political domain if and only if conflicted voters are pivotal and the parties have shared ideological views. Otherwise, we show that candidates may converge or diverge depending upon the degree of party polarization and whether candidates care about ideology or not. Our analysis suggests that the behavior of conflicted voters may be relevant for electoral outcomes and public choice.
Keywords Party polarization, Electoral competition, Conflicted voters, Party identification, Spatial voting
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Abstract Background: Compared to the number of studies performed in the United States, few studies have been conducted on the link between health insurance and healthcare consumption in Europe, likely because most European countries have compulsory national health insurance (NHI) or a national health service (NHS). Recently, a major French private insurer, offering voluntary complementary coverage in addition to the compulsory NHI, replaced its single standard package with a range of offers from basic coverage (BC) to extended coverage (EC), providing a quasi-natural experiment to test theoretical assumptions about consumption patterns. Methods: Reimbursement claim data from 85,541 insurees were analysed from 2009 to 2018. Insurees who opted for EC were matched to those still covered by BC with similar characteristics. Difference-indifferences (DiD) models were used to compare both the monetary value and physical quantities of healthcare consumption before and after the change in coverage. Results: As expected, the DiD models revealed a strong significant, though transitory (mainly during the first year), increase after the change in coverage for EC insurees, particularly for costly care such as dental prostheses and spectacles. Surprisingly, consumption seemed to precede the change in coverage, suggesting that one possible determinant of opting for more coverage may be previous unplanned expenses. Conclusion: Both catching-up behaviour and moral hazard are likely to play a role in the increase observed in healthcare consumption.
Keywords Difference-in-differences, Exact matching, Longitudinal data, Healthcare consumption, Moral hazard, Complementary health insurance
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Abstract Le marginalisme autrichien a pénétré en Ukraine dès la fin du xixe et le début du xxe siècle à travers la théorie de l’utilité développée par l’économiste et mathématicien Yevgen Slutsky. Sa Théorie de l’utilité marginale montre comment les idées autrichiennes majeures y furent reçues et reprises. Slutsky abordait l’économie en scientifique avec une réception critique de la théorie subjective de la valeur élaborée par Carl Menger. Slutsky développa son propre concept de valeur, qu’il présenta dans sa Critique du concept de valeur. Les auteurs se basent sur un matériau inédit conservé dans des archives à Kiev. Slutsky débattit les positions d’Eugen Böhm-Bawerk, il « objectiva » la fonction d’utilité et il souligna le rôle du comportement de consommation au sein du marché. Ses découvertes exercèrent une grande influence : les « équations de Slutsky », l’« effet Slutsky-Yule » et le « théorème de Slutsky » en témoignent.
Keywords Grenznutztheorie, Slutsky Yevgen, Ukraine, Slutsky Yevgen, Economic theory, Marginal utility, Ukraine, Slutsky Yevgen, Théorie économique, Utilité marginale, Ukraine
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