Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Political activism and polarizationJournal articleRaghul S. Venkatesh, Journal of Public Economic Theory, Forthcoming

I develop a model of activism and polarization in the context of electoral competition. Two candidates simultaneously announce policy platforms and seek the support of ideologically inclined activists. Activists compete to influence electoral outcomes by expending costly support for their respective candidates. The presence of activists always moderates the platform choice of candidates, compared to the case of no activism. The central finding of the paper is that the relationship between partisanship of activists and polarization isambiguous. As activists become increasingly partisan, polarization of candidate platforms reduces or widens depending on the costs of activism. I present normative conditions under which the presence of activism and increased partisanship among activists are both welfare-improving for voters. Finally, introducing a public funding option for candidates increases polarization in the political process.

From firm to global-level pollution control: The case of transboundary pollutionJournal articleRaouf Boucekkine, Giorgio Fabbri, Salvatore Federico et Fausto Gozzi, European Journal of Operational Research, Forthcoming

We study the joint determination of optimal investment and optimal depollution in a spatiotemporal framework where pollution is transboundary. Pollution is controlled at a global level. The regulator internalizes that: (i) production generates pollution, which is bad for the wellbeing of population, and that (ii) pollution flows across space driven by a diffusion process. We solve analytically for the optimal investment and depollution spatiotemporal paths and characterize the optimal long-term spatial distribution when relevant. We finally explore numerically the variety of optimal spatial distributions obtained using a core/periphery model where the core differs from the periphery either in terms of input productivity, depollution efficiency, environmental awareness or self-cleaning capacity of nature. We also compare the distributions with and without diffusion. Key aspects in the optimal policy of the regulator are the role of aversion to inequality, notably leading to smoothing consumption across locations, and the control of diffusive pollution adding another smoothing engine.

Exchange rate policy and external vulnerabilities in Sub-Saharan Africa: nominal, real or mixed targeting?Journal articleFadia Al Hajj, Gilles Dufrénot et Benjamin Keddad, Applied Economics, pp. 1-20, Forthcoming

This paper discusses the theoretical choice of exchange rate regimes in Sub-Saharan African countries that are facing external vulnerabilities. To reduce instability, policymakers choose among promoting external competitiveness using a real anchor, lowering the burden of foreign debt using a nominal anchor or using a policy mix of both anchors. We observe that these countries tend to adopt mixed anchor policies. We solve a state space model to explain the determinants of and the strategy behind this policy. We find that the mixed targeting policy is a two-step strategy: First, monetary authorities choose the degree of nominal exchange rate flexibility according to the velocity of money, trade openness, foreign debt, degree of exchange rate pass-through and exchange rate target zone. Second, authorities seek to stabilize the real exchange rate depending on the degree of competition in the domestic goods market and the degree of foreign exchange intervention. We conclude with regime-switching estimations to provide empirical evidence of how these economic fundamentals influence exchange rate policy in Sub-Saharan Africa.

Reproductive health, fairness, and optimal policiesJournal articleJohanna Etner, Natacha Raffin et Thomas Seegmuller, Journal of Public Economic Theory, Volume n/a, Issue n/a, Forthcoming

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.

Economic, Mental Health, HIV Prevention and HIV Treatment Impacts of COVID-19 and the COVID-19 Response on a Global Sample of Cisgender Gay Men and Other Men Who Have Sex with MenJournal articleGlenn-Milo Santos, Benjamin Ackerman, Amrita Rao, Sara Wallach, George Ayala, Erik Lamontage, Alex Garner, Ian W. Holloway, Sonya Arreola, Vince Silenzio, et al., Aids and Behavior, Forthcoming

There is an urgent need to measure the impacts of COVID-19 among gay men and other men who have sex with men (MSM). We conducted a cross-sectional survey with a global sample of gay men and other MSM (n = 2732) from April 16, 2020 to May 4, 2020, through a social networking app. We characterized the economic, mental health, HIV prevention and HIV treatment impacts of COVID-19 and the COVID-19 response, and examined whether sub-groups of our study population are disproportionately impacted by COVID-19. Many gay men and other MSM not only reported economic and mental health consequences, but also interruptions to HIV prevention and testing, and HIV care and treatment services. These consequences were significantly greater among people living with HIV, racial/ethnic minorities, immigrants, sex workers, and socio-economically disadvantaged groups. These findings highlight the urgent need to mitigate the negative impacts of COVID-19 among gay men and other MSM.

On Zipf's law and the bias of Zipf regressionsJournal articleChristian Schluter, Empirical Economics, Forthcoming

City size distributions are not strictly Pareto, but upper tails are rather Pareto like (i.e. tails are regularly varying). We examine the properties of the tail exponent estimator obtained from ordinary least squares (OLS) rank size regressions (Zipf regressions for short), the most popular empirical strategy among urban economists. The estimator is then biased towards Zipf's law in the leading class of distributions. The Pareto quantile-quantile plot is shown to offer a simple diagnostic device to detect such distortions and should be used in conjunction with the regression residuals to select the anchor point of the OLS regression in a data-dependent manner. Applying these updated methods to some well-known data sets for the largest cities, Zipf's law is now rejected in several cases.

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, Forthcoming

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.

Information Provision in Environmental Policy DesignJournal articleVera Danilina et Alexander Grigoriev, Journal of environmental informatics, Forthcoming

Information provision is a relatively recent but steadily growing environmental policy tool. Its emergency and topicality are due to the current escalation of ecological threats. Meanwhile, its high complexity and flexibility require a comprehensive approach to its design, which has to be tailored for specific characteristics of production process, market structure, and regulatory goals. This work proposes such an approach and builds a framework based on a three-level mathematical program extending well-known two-level Stackelberg game by introducing one more economic agent and one extra level of this sequential game. This study provides simple and very intuitive algorithms to compute optimal multi-tier information provision policies, both mandatory and voluntary. The paper urges for the wide implementation of such efficient environmental policy design tools.

God insures those who pay? Formal insurance and religious offerings in Ghana.Journal articleEmmanuelle Auriol, Julie Lassébie, Amma Panin, Eva Raiber et Paul Seabright, Quarterly Journal of Economics, Forthcoming

This paper provides experimental support for the hypothesis that insurance can be a motive for religious donations. We randomize enrollment of members of a Pentecostal church in Ghana into a commercial funeral insurance policy. Then church members allocate money between themselves and a set of religious goods in a series of dictator games with significant stakes. Members enrolled in insurance give significantly less money to their own church compared to members that only receive information about the insurance. Enrollment also reduces giving towards other spiritual goods. We set up a model exploring different channels of religiously based insurance.
The implications of the model and the results from the dictator games suggest that adherents perceive the church as a source of insurance and that this insurance is derived from beliefs in an interventionist God. Survey results suggest that material insurance from the church community is also important and we hypothesize that these two insurance channels exist in parallel.

The Welfare Consequences of Centralization: Evidence from a Quasi-Natural Experiment in SwitzerlandJournal articleSarah Flèche, Review of Economics and Statistics, Forthcoming

Many countries are reallocating tasks and powers to more central levels of government. To identify centralization’s welfare effects, I use a difference-in-differences design that relies on time and cross-cantonal variation in the implementation of centralization reforms in Switzerland. I find that centralization provokes significant decreases in residents’ life satisfaction. I identify one mechanism driving the effect, namely the procedural disutility that individuals experience from having less influence over the formulation of political decisions. This effect is largest among individuals with higher expected benefits from being involved in the political decision process, with detrimental effects on local political participation.