Calendrier du 04 décembre 2023
Roy Seminar (ADRES)
Du 04/12/2023 de 17:00 à 18:30
R1-09
SANDMANN Christopher (LSE)
Market Structure and Adverse Selection (with Dakang Huang)
This paper adopts a uni?ed perspective on multi-contracting in competitive markets plagued by adverse selection. We subsume the two polar cases of exclusive and nonexclu-sive competition by introducing the concept of a market structure, i.e., a trading rule thatspeci?es the subset of sellers with whom buyers can jointly trade. The existing literature shows that the market structure matters greatly in shaping competitive allocations, allow-ing for either separating allocations (as shown by Rothschild-Stiglitz) or layered pooling(Jaynes-Hellwig-Glosten) allocations. We prove the existence of intermediate “Pooling +Separating” equilibria that allow for simultaneous pooling and low-risk buyer separation.Crucially, those allocations alleviate at the same time the concern of excessive rationing under separation of and cross-subsidies paid by low-risk buyers. They oftentimes Pareto dominate the Rothschild-Stiglitz separating allocation. Our analysis singles out the “1+1”market structure where sellers are separated into two subgroups so that buyers can trade with at most one seller from each subgroup. Any “Pooling + Separating” allocation is an equilibrium here. Finally, we prove that “Pooling + Separating” allocations satisfy a notion of stability that we call serendipitous-aftermarket-proofness.
Econometrics Seminar
Du 04/12/2023 de 16:15 à 17:30
ZOOM
FORNERON Jean-Jacques (Boston University)
Occasionally Misspecified
When fitting a particular Economic model on a sample of data, the model may turn out to be heavily misspecified for some observations. This can happen because of unmodelled idiosyncratic events, such as an abrupt but short-lived change in policy. These outliers can significantly alter estimates and inferences. A robust estimation is desirable to limit their influence. For skewed data, this induces another bias which can also invalidate the estimation and inferences. This paper proposes a robust GMM estimator with a simple bias correction that does not degrade robustness significantly. The paper provides finite-sample robustness bounds, and asymptotic uniform equivalence with an oracle that discards all outliers. Consistency and asymptotic normality ensue from that result. An application to the “Price-Puzzle,” which finds inflation increases when monetary policy tightens, illustrates the concerns and the method. The proposed estimator finds the intuitive result: tighter monetary policy leads to a decline in inflation.
Texte intégral
Paris Migration Economics Seminar
Du 04/12/2023 de 12:30 à 13:30
R1.14
DUPAS Pascaline()
ROSSI Pauline(Ecole Polytechnique - CREST)
FALEZAN Camille()
MABEU Marie Christelle()
Long-run Impacts of Forced Labor Migration on Fertility Behaviors: Evidence from Colonial West Africa
Is the persistently high fertility in West Africa today rooted in the decades of forced labor migration
under colonial rule? We study the case of Burkina Faso, considered the largest labor reservoir in West
Africa by the French colonial authorities. Hundreds of thousands of young men were forcibly recruited
and sent to work in neighboring colonies for one or two years. The practice started in the late 1910s
and lasted until the late 1940s, when forced labor was replaced with voluntary wage employment. We
digitize historical maps, combine data from multiple surveys, and exploit the historical, temporary
partition of colonial Burkina Faso (and, more specifically, the historical land of the Mossi ethnic group)
into three zones with different needs for labor to implement a spatial regression discontinuity design
analysis. We find that, on the side of the border where Mossi villages were more exposed to forced labor
historically, there is more temporary male migration to Cote d’Ivoire up to today, and lower realized
and desired fertility today. We show evidence suggesting that the inherited pattern of low-skill circular
migration for adult men reduced the reliance on subsistence farming and the accompanying need for
child labor. We can rule out women’s empowerment or improvements in human and physical capital
as pathways for the fertility decline. These findings contribute to the debate on the origins of family
institutions and preferences, often mentioned to explain West Africa’s exceptional fertility trends,
showing that decisions on family formation can change if modes of production change.
Régulation et Environnement
Du 04/12/2023 de 12:00 à 13:30
R1-09
DURRMEYER Isis (TSE)
*The Welfare Consequences of Urban Traffic regulations
écrit avec Nicolas Martinez
We develop a structural model to represent individual transportation decisions, the equilibrium road traffic levels, and speeds inside a city. The model is micro-founded and incorporates a high level of heterogeneity: individuals differ in access to transportation modes, values of travel time, and schedule constraints; road congestion technologies vary within the city. We apply our model to the Paris metropolitan area and estimate the model parameters from publicly available data. We predict the road traffic equilibria under driving restrictions and road tolls and measure the policy consequences on the different welfare components: individual surplus, tax revenues, and cost of emissions.