Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Heterogeneity and nonconstant effect in two-stage quantile regressionJournal articleChristophe Muller, Econometrics and Statistics, Volume 8, Issue C, pp. 3-12, 2018

Heterogeneity in how some independent variables affect a dependent variable is pervasive in many phenomena. In this respect, this paper addresses the question of constant versus nonconstant effect through quantile regression modelling. For linear quantile regression under endogeneity, it is often believed that the fitted-value setting (i.e., replacing endogenous regressors with their exogenous fitted-values) implies constant effect (that is: the coefficients of the covariates do not depend on the considered quantile, except for the intercept). Here, it is shown that, under a weakened instrumental variable restriction, the fitted-value setting can allow for nonconstant effect, even though only the constant-effect coefficients of the model can be identified. An application to food demand estimation in 2012 Egypt shows the practical potential of this approach.

Forecasting Bordeaux wine prices using state-space methodsJournal articleStephen Bazen et Jean-Marie Cardebat, Applied Economics, Volume 50, Issue 47, pp. 5110-5121, 2018

Generic Bordeaux red wine (basic claret) can be regarded as being similar to an agricultural commodity. Production volumes are substantial, they are traded at high frequency and the quality of the product is relatively homogeneous. Unlike other commodities and the top-end wines (which represent only 3% of the traded volume), there is no futures market for generic Bordeaux wine. Reliable forecasts of prices can to large extent replace this information deficiency and improve the functioning of the market. We use state-space methods with monthly data to obtain a univariate forecasting model for the average price. The estimates highlight the stochastic trend and the seasonality present in the evolution of the price over the period 1999 to 2016. The model predicts the path of wine prices out of sample reasonably well, suggesting that this approach is useful for making reasonably accurate forecasts of future price movements.

The impact of the 2014 increase in the real estate transfer taxes on the French housing marketJournal articleGuillaume Bérard et Alain Trannoy, Economie et Statistique / Economics and Statistics, Issue 500-501-502, pp. 179-200, 2018

This paper estimates the effects of an increase in the share of the real estate transfer taxes (RETT) going to the French départements from 3.80% to 4.50%. Not all the départements voted the RETT increase on the same date, which is the starting point of a natural experiment. Using a difference-in-differences design, we estimate two main effects. (1) An anticipation effect, one month before the implementation of the reform, in order to avoid the RETT increase. (2) A retention effect in the post-reform period. In the end, the net effect (retention minus anticipation) corresponds to an average drop in transactions of around 6% over the first three months after the reform, that is, approximately 15,000 transactions lost at national level. If we find a short term effect of the reform, we do not find evidence of a medium- or long-term effect.

A socioecological measurement of homophobia for all countries and its public health impactJournal articleErik Lamontagne, Marc d'Elbée, Michael W. Ross, Aengus Carroll, André du Plessis et Luiz Loures, European Journal of Public Health, Volume 28, Issue 5, pp. 967-972, 2018

Background:
Measuring homophobia at country level is important to guide public health policy as reductions in stigma are associated with improved health outcomes among gay men and other men who have sex with men. Methods: We developed a Homophobic Climate Index incorporating institutional and social components of homophobia. Institutional homophobia was based on the level of enforcement of laws that criminalise, protect or recognise same-sex relations. Social homophobia was based on the level of acceptance and justifiability of homosexuality. We estimated the Index for 158 countries and assessed its robustness and validity.

Results:
Western Europe is the most inclusive region, followed by Latin America. Africa and the Middle East are home to the most homophobic countries with two exceptions: South Africa and Cabo Verde. We found that a 1% decrease in the level of homophobia is associated with a 10% increase in the gross domestic product per capita. Countries whose citizens face gender inequality, human rights abuses, low health expenditures and low life satisfaction are the ones with a higher homophobic climate. Moreover, a 10% increase in the level of homophobia at country level is associated with a 1.7-year loss in life expectancy for males. A higher level of homophobia is associated with increased AIDS-related death among HIV-positive men.

Conclusion:
The socioecological approach of this index demonstrates the negative social, economic and health consequences of homophobia in low- and middle-income countries. It provides sound evidence for public health policy in favour of the inclusion of sexual minorities.

Constitutional rules as determinants of social infrastructureJournal articleTheo S. Eicher, Cecilia Garcia-Peñalosa et David J. Kuenzel, Journal of Macroeconomics, Volume 57, Issue C, pp. 182-209, 2018

A sizable literature has established the positive impact of social infrastructure on economic development, but the determinants of social infrastructure itself have yet to be fully explored. Competing theories suggest a variety of political institutions as driving forces of social infrastructure, but the empirical literature has been hampered by the small set of available proxies, many of which are broadly defined. We leverage a new, comprehensive dataset that codes political institutions directly from countries’ constitutions. By employing a statistical methodology that is designed to juxtapose candidate regressors associated with many competing theories, we test each individual political institution's effect on social infrastructure. Our results show that constitutional rules pertaining to executive constraints as well as to the structure of electoral systems are crucial for the development of high-quality social infrastructure. We also find that the determinants of social infrastructure are much more fundamental than previously thought: not only the general structure of electoral systems matter, but also highly detailed aspects such as limits on campaign contributions and the freedom to form parties. Moreover, the granularity of our data allows us to highlight the profound effect of basic human rights on social infrastructure, a dimension which has not been explored in the literature to date.

Coordination with communication under oathJournal articleNicolas Jacquemet, Stéphane Luchini, Jason F. Shogren et Adam Zylbersztejn, Experimental Economics, Volume 21, Issue 3, pp. 627-649, 2018

We focus on the design of an institutional device aimed to foster coordination through communication. We explore whether the social psychology theory of commitment, implemented via a truth-telling oath, can reduce coordination failure. Using a classic coordination game, we ask all players to sign voluntarily a truth-telling oath before playing the game with cheap talk communication. Three results emerge with commitment under oath: (1) coordination increased by nearly 50%; (2) senders’ messages were significantly more truthful and actions more efficient, and (3) receivers’ trust of messages increased.

Strategic Product Design under DuopolyJournal articleDidier Laussel, Annals of Economics and Statistics, Issue 131, pp. 25-44, 2018

Two duopolists first decide in which proportions to incorporate in their product two different Lancasterian characteristics and then compete in quantities or prices. In the Cournot case, minimum differentiation obtains at equilibrium whatever the degree of substituability between the characteristics. In the Bertrand one, the equilibrium depends crucially on the degree of substituability/complementarity between the two characteristics. Maximal differential obtains if and only if the characteristics are strong enough substitutes. On the contrary as characteristics become closer and closer complements one obtains in the limit a minimal differentiation result. JEL Codes: L13. Keyword: Horizontal Product Differentiation, Lancasterian Characteristics.

Reducing the anchoring bias in multiple question CV surveysJournal articleVictor Champonnois, Olivier Chanel et Khaled Makhloufi, Journal of Choice Modelling, Volume 28, Issue C, pp. 1-9, 2018

The elicitation format is a crucial aspect of Contingent Valuation (CV) surveys and can impact their reliability. This paper contributes to the extensive debate on WTP (Willingness To Pay) elicitation formats by assessing whether the Circular Payment Card (CPC) can reduce anchoring on respondents' previous answers under multiple elicitation questions. This new format uses a visual pie-chart representation without start or end points: respondents spin the circular card in any direction until they find the section that best matches their WTP. We used a CV survey based on two ways of reducing risks associated with flooding, each randomly presented first to half of the respondents, to test the absolute performance of CPC. We presented a second survey on two social insurance schemes for subjects currently uninsured to respondents randomly split into three subgroups. Each group's WTP was elicited using one of three formats: Open-Ended (OE), standard Payment Card (PC) and the new CPC. The two insurance schemes were always proposed in the same order, and we assessed the relative performance of CPC by comparing anchoring across respondents. Our results provide evidence that CPC is likely to reduce anchoring in multiple elicitation questions and that respondents may rely on different heuristic decisions when giving WTP in the OE and in the two PC formats.

Un diagnostic de gouvernance basé sur le discours des acteurs : le cas du littoral marseillais « côté mer » (Marseille, France)Journal articleDominique Ami, Juliette Rouchier et Stéphane Calandra, VertigO : La Revue Électronique en Sciences de l'Environnement, Volume 18, Issue 2, 2018

Nous étudions ici le discours que certains acteurs du littoral marseillais (des usagers, des élus et des gestionnaires) ont de la gouvernance de la zone, en nous penchant en particulier sur l’institution (l’ensemble des règles) telle qu’elle est perçue et comment les divers acteurs sont vus comme plus ou moins légitimes. Nous utilisons pour cela le cadre d’analyse Institutional Analysis and Development construit par Elinor Ostrom pour analyser des entretiens semi-directifs menés en 2013. Nous avons en particulier identifié la description des usages, des acteurs, des conflits et des nuisances, ainsi que la répartition des rôles de définition des règles et d’autorité. Nous notons plusieurs éléments importants : les acteurs partagent un objectif affiché de protection du littoral identifié comme un espace très fréquenté, fragile, entre terre et mer, ils identifient un acteur central légitime (le Parc national des Calanques, pourtant à peine en fonction à l’époque) comme meneur de la gouvernance, et définissent également des usagers extérieurs non légitimes (les touristes, les pollueurs) comme acteurs qui ne partagent pas les objectifs de locaux. Les règles opérationnelles sont relativement peu remises en cause alors qu’il existe une certaine incompréhension et même une confusion pour les règles de choix collectifs et les règles constitutionnelles. Ces dernières, qui permettent de penser la dynamique des institutions semblent avoir disparu depuis la création du Parc national, ce qui signale une gouvernance imparfaite, mais permet aussi d’indiquer un chemin pour l’améliorer.

A dynamic network analysis of the world oil market: Analysis of OPEC and non-OPEC membersJournal articleSahel Al Rousan, Rashid Sbia et Bedri Kamil Onur Tas, Energy Economics, Volume 75, Issue C, pp. 28-41, 2018

We characterize the dynamic network structure of major oil producing countries. We examine the oil production coordination of 13 Organization of the Petroleum Exporting Countries (OPEC) and 17 non-OPEC members. We construct the dynamic network structure using the network connectedness measure of Diebold and Yilmaz (2009). We investigate the structural changes in connectedness of OPEC and non-OPEC members. Additionally, we study how the influence of OPEC members, non-OPEC countries and major oil producers evolve. We find that the network structure of major oil-producing countries changes significantly over time. Specifically, the impact of changes in oil-production of all OPEC members on global oil production declines, whereas the impact of non-OPEC on global oil production increases. OPEC's “increase” decisions have a significant and positive impact on OPEC and non-OPEC coordination. However, “cut” decisions do not affect coordination. We find that OPEC countries and developing countries have significantly higher levels of connectedness. Additionally, countries with high oil production levels have significantly more influence. The empirical results provide intuition about the recent developments in global oil production.