Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Reproductive health, fairness, and optimal policiesJournal articleJohanna Etner, Natacha Raffin et Thomas Seegmuller, Journal of Public Economic Theory, Volume 22, Issue 5, pp. 1213-1244, 2020

We consider an overlapping generations economy in which agents differ through their ability to procreate. Ex-ante infertile households may incur health expenditure to increase their chances of parenthood. This health heterogeneity generates welfare inequalities that deserve to be ruled out. We explore three different criteria of social evaluation in the long-run: the utilitarian approach, the ex-ante egalitarian criterion and the ex-post egalitarian one. We propose a set of economic instruments to decentralize each solution. To correct for the externalities and health inequalities, both a preventive (a taxation of capital) and a redistributive policy are required. We show that a more egalitarian allocation is associated with higher productive investment but reduced health expenditure and thus, lower population growth.

How helpful are social networks in finding a job along the economic cycle? Evidence from immigrants in FranceJournal articleEva Moreno Galbis, Francois-Charles Wolff et Arnaud Herault, Economic Modelling, Volume 91, pp. 12-32, 2020

Around 50% of individuals obtain or hear about jobs through social networks. This hiring trend may become problematic when the labor market is tight and people need less social contacts to find a job. Using a one-period static model where network members may receive job offers directly from the firm or indirectly through employed members in the network we show that the share of new hires finding a job through social connections (ie network matching rate) decreases with the job finding rate. Using French data for the period 2003-2012, we test this prediction with immigrants, a population subgroup for whom networks play a major role in occupational decisions. We propose two network matching rate indicators, one based on direct recommendations and another one internalizing the positive externality on the employment probability induced by peers. We find a decreasing relationship between the network matching rate and the job finding rate. Social connections are less helpful for finding jobs during economic expansions.

La gouvernance par les valeurs comme élément de performance des organisations de l'ESS. L'éclairage postmoderneJournal articleArnaud Lacan et François Silva, Recherches en Sciences de Gestion - Management Sciences - Ciencias de Gestión, Issue 137, pp. 317-337, 2020

Cet article présente une réflexion générale sur la gouvernance et les pratiques managériales dans le domaine de l’économie sociale et solidaire (ESS) et suggère que, dans une période de mutations socioéconomiques profonde, les entreprises de l’ESS ont intérêt à mettre en place une gouvernance globale et un management des équipes qui soit cohérents avec les valeurs structurantes de son univers et les aspirations de leurs collaborateurs.

Mémoire longue dans les séries financières (Chapitre 2)Book chapterMarcel Aloy, Gilles Dufrénot et Anne Péguin-Feissolle, In: Méthodes de prévisions en finance, A. Charles, O. Darné et L. Ferrara (Eds.), 2020-09, pp. 29-52, 2020
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, Volume 284, Issue 3, pp. 990-1001, 2020

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.

Peer Effects in Networks: A SurveyJournal articleYann Bramoullé, Habiba Djebbari et Bernard Fortin, Annual Review of Economics, Volume 12, Issue 1, pp. 603-629, 2020

We survey the recent, fast-growing literature on peer effects in networks. An important recurring theme is that the causal identification of peer effects depends on the structure of the network itself. In the absence of correlated effects, the reflection problem is generally solved by network interactions even in nonlinear, heterogeneous models. By contrast, microfoundations are generally not identified. We discuss and assess the various approaches developed by economists to account for correlated effects and network endogeneity in particular. We classify these approaches in four broad categories: random peers, random shocks, structural endogeneity, and panel data. We review an emerging literature relaxing the assumption that the network is perfectly known. Throughout, we provide a critical reading of the existing literature and identify important gaps and directions for future research.

Simulating the progression of the COVID-19 disease in Cameroon using SIR modelsJournal articleUlrich Nguemdjo, Freeman Meno, Audric Dongfack et Bruno Ventelou, PLoS ONE, Volume 15, Issue 8, pp. e0237832, 2020

This paper analyses the evolution of COVID-19 in Cameroon over the period March 6-April 2020 using SIR models. Specifically, we 1) evaluate the basic reproduction number of the virus, 2) determine the peak of the infection and the spread-out period of the disease, and 3) simulate the interventions of public health authorities. Data used in this study is obtained from the Cameroonian Public Health Ministry. The results suggest that over the identified period, the reproduction number of COVID-19 in Cameroon is about 1.5, and the peak of the infection should have occurred at the end of May 2020 with about 7.7% of the population infected. Furthermore, the implementation of efficient public health policies could help flatten the epidemic curve.

Gender norms, fairness and relative working hours within householdsJournal articleSarah Flèche, Anthony Lepinteur et Nattavudh Powdthavee, Labour Economics, Volume 65, pp. 101866, 2020

Using data in the United States, UK and Germany, we show that women whose working hours exceed those of their male partners report lower life satisfaction on average. By contrast, men do not report lower life satisfaction from working more hours than their female partners. An analysis of possible mechanisms shows that in couples where the woman works more hours than the man, women do not spend significantly less time doing household chores. Women with egalitarian ideologies are likely to perceive this unequal division of labour as unfair, ultimately reducing their life satisfaction.

Who bears the burden of universal health coverage? An assessment of alternative financing policies using an overlapping-generations general equilibrium modelJournal articleMohammad Abu-Zaineh, Sameera Awawda et Bruno Ventelou, Health Policy and Planning, Volume 35, Issue 7, pp. 867-877, 2020

In their quest for universal health coverage (UHC), many developing countries use alternative financing strategies including general revenues to expand health coverage to the whole population. Unless a policy adjustment is undertaken, future generations may foot the bill of the UHC. This raises the important policy questions of who bears the burden of UHC and whether the UHC-fiscal stance is sustainable in the long term. These two questions are addressed using an overlapping generations model within a general equilibrium (OLG-CGE) framework applied to Palestine. We assess and compare alternative ways of financing the UHC-ridden deficit (viz. deferred-debt, current and phased-manner finance) and their implications on fiscal sustainability and intergenerational inequalities. The policy instruments examined include direct labour-income tax and indirect consumption taxes as well as health insurance contributions. Results show that in the absence of any policy adjustment, the implementation of UHC would explode the fiscal deficit and debt-GDP ratio. This indicates that the UHC-fiscal stance is rather unsustainable in the long term, thus, calling for a policy adjustment to service the UHC debt. Among the policies we examined, a current rather than deferred-debt finance through consumption taxation emerged to be preferred over other policies in terms of its implications for both fiscal sustainability and intergenerational inequality.

Volatility estimation and jump detection for drift–diffusion processesJournal articleSébastien Laurent et Shuping Shi, Journal of Econometrics, Volume 217, Issue 2, pp. 259-290, 2020

The logarithmic prices of financial assets are conventionally assumed to follow a drift–diffusion process. While the drift term is typically ignored in the infill asymptotic theory and applications, the presence of temporary nonzero drifts is an undeniable fact. The finite sample theory for integrated variance estimators and extensive simulations provided in this paper reveal that the drift component has a nonnegligible impact on the estimation accuracy of volatility, which leads to a dramatic power loss for a class of jump identification procedures. We propose an alternative construction of volatility estimators and observe significant improvement in the estimation accuracy in the presence of nonnegligible drift. The analytical formulas of the finite sample bias of the realized variance, bipower variation, and their modified versions take simple and intuitive forms. The new jump tests, which are constructed from the modified volatility estimators, show satisfactory performance. As an illustration, we apply the new volatility estimators and jump tests, along with their original versions, to 21 years of 5-minute log returns of the NASDAQ stock price index.