Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Collective risk-taking by couples: individual vs household riskJournal articleJiakun Zheng, Hélène Couprie et Astrid Hopfensitz, Theory and Decision, 2025

101 real couples participated in a controlled experimental risk-taking task involving variations in household and individual income risks, while controlling for ex-ante income inequality. Our design disentangles the effects of household risk, intra-household risk inequality, and ex-post payoff inequality. We find that most couples (about 79%) pooled their risk at the household level when risks were borne symmetrically, but a significant proportion of couples (about 36%) failed to do so when individual risks were borne asymmetrically. Additionally, within the scope of the control variables we have utilized, we find that intra-household risk inequality has a larger impact on non-married couples compared to married ones. These results remain robust when the analysis is limited to couples in which both spouses are risk-averse. Lastly, we find that preferences for household efficiency are significantly correlated across both certain and risky situations. However, couples consisting of two income-maximizing spouses do not show greater aversion to risk inequality compared to couples with other compositions.

The Percolation of Knowledge across SpaceJournal articlePierre Cotterlaz et Arthur Guillouzouic, Journal of International Economics, Volume 153, pp. 104026, 2025

This paper shows that the negative effect of geographical distance on knowledge flows stems from how firms gain sources of knowledge through their existing network. We start by documenting two stylized facts. First, in aggregate, the distance elasticity of patent citations flows is sizable and has remained constant since the 1980s, despite the rise of the internet. Second, at the micro level, firms’ network of knowledge sources expands through existing knowledge sources. We introduce a framework featuring the latter phenomenon, and generating a negative distance elasticity in aggregate. The model predicts Pareto-distributed innovator sizes, and citation distances increasing with innovator size. These predictions hold well empirically. We investigate changes of the underlying parameters and geographical composition effects over the period. While the distance effect should have decreased with constant country composition, the rise of East Asian economies, associated to large distance elasticities, compensated lower frictions in other countries.

Directional Tests and Confidence Bounds on Economic InequalityJournal articleJean-Marie Dufour, Emmanuel Flachaire, Lynda Khalaf et Abdallah Zalghout, Econometrics and Statistics, Volume 33, pp. 230-245, 2025

For standard inequality measures, distribution-free inference methods are valid under conventional assumptions that fail to hold in applications. Resulting Bahadur-Savage type failures are documented, and correction methods are provided. Proposed solutions leverage on the positive support prior that can be defended with economic data such as income, in which case directional non-parametric tests can be salvaged. Simulation analysis with generalized entropy measures allowing for heavy tails and contamination reveals that proposed lower confidence bounds provide concrete size and power improvements, particularly through bootstraps. Empirical analysis on within-country wage inequality and on world income inequality illustrates the usefulness of the proposed lower bound, as opposed to the erratic behavior of traditional upper bounds.

Where and why do politicians send pork? Evidence from central government transfers to French municipalitiesJournal articleBrice Fabre et Marc Sangnier, Journal of Public Economics, Volume 241, pp. 105276, 2025

This paper uses French data to simultaneously estimate the impact of two types of connections on government subsidies allocated to municipalities. Investigating different types of connection in a same setting helps to distinguish between the different motivations that could drive pork-barreling. We differentiate between municipalities where ministers held office before their appointment to the government and those where they lived as children. Exploiting ministers’ entries into and exits from the government, we show that municipalities where a minister was mayor receive 30% more investment subsidies when the politician they are linked to joins the government, and a similar size decrease when the minister departs. In contrast, we do not observe these outcomes for municipalities where ministers lived as children. These findings indicate that altruism toward childhood friends and family does not fuel pork-barreling, and suggest that altruism toward adulthood social relations or career concerns matter. We also present complementary evidence suggesting that observed pork-barreling is the result of soft influence of ministers, rather than of their formal control over the administration they lead.

Valuing mortality risk reductions in the time of COVID-19: A stated-preference analysisJournal articleJianhua Xu, Shiwei Fan et Jiakun Zheng, Risk Sciences, Volume 1, pp. 100007, 2025

Lack of high-quality value per statistical life (VSL) studies in low- and middle-income countries have been recognized by scholars and analysts in the benefit-cost analysis field for decades. However, progress has been slow in addressing it. We estimated VSL in China using a stated-preference survey in the context of reducing mortality risks associated with COVID-19. The survey was administered in seven cities across China in 2022 with a purposive sampling approach, and consistency checks at different levels of stringency regarding willingness to pay (WTP) for mortality risk reductions of different magnitudes were used to screen respondents. The estimated VSL ranges from 8.0 million to 10.3 million Chinese Yuan, which is higher than previous estimates. Also previous studies found much higher VSL estimates from a subsample obtained with more stringent consistency check requiring that WTP be approximately proportional to the magnitude of mortality risk reduction, we did not find such a difference with our dataset. In addition, based on our anlaysis, respondents in first-tier cities such as Beijing, Shanghai and Guangzhou have higher VSL than those in second-tier cities such as Changchun, Chengdu, Wuhan and Xi’an; the VSL-age relationship shows a U-shaped pattern; and the collective experience of city lockdown has a negative impact on VSL. Other factors which were found to influence VSL include education, sector of work, health status, risk perception, behaviors (physical exercises, wearing face masks, getting vaccinated), knowledge, political identity, and trust in government.
JEL classification codes
I12, I18

Routes to the TopJournal articleJohannes König, Christian Schluter et Carsten Schröder, Review of Income and Wealth, Volume 71, Issue 2, pp. e70015, 2025

Who makes it to the top? We use the leading socio-economic survey in Germany, supplemented by extensive data on the rich, to answer this question. We identify the key predictors for belonging to the top 1 percent of income, wealth, and both distributions jointly. Although we consider many, only a few traits matter: Entrepreneurship and self-employment in conjunction with a sizable inheritance of company assets is the most important covariate combination across all rich groups. Our data suggest that all top 1 percent groups, but especially the joint top 1 percent, are predominantly populated by intergenerational entrepreneurs.

Clustering Approaches for Mixed-Type Data: A Comparative StudyJournal articleBadih Ghattas et Alvaro Sanchez San-Benito, Journal of Probability and Statistics, Volume 2025, Issue 1, pp. 2242100, 2025

Clustering is widely used in unsupervised learning to find homogeneous groups of observations within a dataset. However, clustering mixed-type data remains a challenge, as few existing approaches are suited for this task. This study presents the state-of-the-art of these approaches and compares them using various simulation models. The compared methods include the distance-based approaches k-prototypes, PDQ, and convex k-means, and the probabilistic methods KAy-means for MIxed LArge data (KAMILA), the mixture of Bayesian networks (MBNs), and latent class model (LCM). The aim is to provide insights into the behavior of different methods across a wide range of scenarios by varying some experimental factors such as the number of clusters, cluster overlap, sample size, dimension, proportion of continuous variables in the dataset, and clusters’ distribution. The degree of cluster overlap and the proportion of continuous variables in the dataset and the sample size have a significant impact on the observed performances. When strong interactions exist between variables alongside an explicit dependence on cluster membership, none of the evaluated methods demonstrated satisfactory performance. In our experiments KAMILA, LCM, and k-prototypes exhibited the best performance, with respect to the adjusted rand index (ARI). All the methods are available in R.

A Variational Rationality Perspective on the Quasi-Equilibrium Problem: Climbing the Goal LadderJournal articleAntoine Soubeyran et Jo Carlos De Souza, Journal of Nonlinear and Variational Analysis, Volume 9, Issue 3, pp. 461-478, 2025

In this paper, we examine the quasi-equilibrium problem from a variational rationality perspective. To this end, we first study the convergence of the proximal point method proposed by Bento et al. [Ann. Oper. Res. 316 (2022), 1301-1318] in the more general context of quasi-equilibrium problems using a Bregman distance. Thus, we provide an application of the method through a recent behavioral perspective, more precisely, the variational rationality approach of staying and changing human dynamics, and the important example of climbing the goal ladder in goal pursuit theory. An illustrative simulation demonstrates that Bregman distances improve the computational performance of the method compared to the Euclidean distance.

Foreign Corrupt Practices Act (FCPA) and market quality in emerging economiesJournal articleKrishnendu Ghosh Dastidar et Makoto Yano, Managerial and Decision Economics, Volume 46, Issue 1, pp. 641-665, 2025

In many emerging economies with antiquated laws, bribes paid to government officials reduce economic impediments and serve as a device to improve market competition, thereby contributing to the modernization of an economy. In this context, this paper uses a simple two-stage game theoretic model to investigate the effects of the US Foreign Corrupt Practices Act (FCPA) on such economies. We demonstrate, among others, that while an increase in fines under FCPA reduces overall corruption, it leads to a deterioration in the market quality in an emerging economy. In the presence of FCPA, an increase in the US firm's technological advantage unambiguously leads to a decrease in the market quality in an emerging economy.

Work organization in social enterprises: A source of job satisfaction?Journal articleXavier Joutard, Francesca Petrella et Nadine Richez-Battesti, Kyklos, Volume 78, Issue 1, pp. 111-148, 2025

Many studies suggest that employees of social enterprises experience greater job satisfaction than employees of for-profit organizations, although their pay and employment contracts are usually less favorable. Based on linked employer–employee data from a French survey on employment characteristics and industrial relations and using a decomposition method developed by Gelbach (2016), this paper aims to explain this somewhat paradoxical result. Focusing on work organization variables, we show that the specific work organization of social enterprises explains a large part of the observed job satisfaction differential both in general and more specifically, in terms of satisfaction with access to training and working conditions. By detailing the components of work organization, the higher job satisfaction reported by employees in social enterprises stems from their greater autonomy and better access to information. In contrast to earlier studies, however, our results show that these work organization variables do not have more value for social enterprise employees than for for-profit organization employees in the case of overall job satisfaction. This result casts doubt on the widespread hypothesis that social enterprise employees attach more weight to the nonmonetary advantages of their work than their counterparts in for-profit organizations.