Calendrier du 10 mai 2021
Paris Migration Seminar
Du 10/05/2021 de 17:30 à 18:20
BAH Tijan (University of Navarra)
How has COVID-19 affected the intention to migrate via the backway to Europe and to a neighboring African country? Survey evidence and a salience experiment in The Gambia
écrit avec joint with Catia Batista, Flore Gubert, David McKenzie
The COVID-19 pandemic has resulted in border closures in many countries and a sharp reduction in overall international mobility. However, this disruption of legal pathways to migration has raised concerns that potential migrants may turn to irregular migration routes as a substitute. We examine how the pandemic has changed intentions to migrate from The Gambia, the country with the highest pre-pandemic per-capita irregular migration rates in Africa. We use a large-scale panel survey conducted in 2019 and 2020 to compare changes in intentions to migrate to Europe and to neighboring Senegal. We find the pandemic has reduced the intention to migrate to both destinations, with approximately one-third of young males expressing less intention to migrate. The largest reductions in migration intentions are for individuals who were unsure of their intent pre-pandemic, and for poorer individuals who are no longer able to afford the costs of migrating at a time when these costs have increased and their remittance income has fallen. We also introduce the methodology of priming experiments to the study of migration intentions, by randomly varying the salience of the COVID-19 pandemic before eliciting intentions to migrate. We find no impact of this added salience, which appears to be because knowledge of the virus, while imperfect, was already enough to inform migration decisions. Nevertheless, despite these decreases in intentions, the overall desire to migrate the backway to Europe remains high, highlighting the need for legal migration pathways to support migrants and divert them from the risks of backway migration.
Roy Seminar (ADRES)
Du 10/05/2021 de 17:00 à 18:00
online
BARDHI Arjada (Duke University)
Local Evidence and Diversity in Minipublics
écrit avec Co-author: Nina Bobkova
We study optimal minipublic design with endogenous evidence. A policymaker selects a group of citizens—a minipublic—for advice on the desirability of a policy. Citizens can discover local evidence but might be deterred by uncertainty about the policymaker’s adoption standard. We show that such uncertainty can be detrimental to evidence discovery even with costless evidence, civic-minded citizens, and ex ante aligned players. Evidence discovery is hardest to sustain under moderate uncertainty. The optimal minipublic has low diversity: it overrepresents citizens around the median citizen and underrepresents those at the margins. Our findings bear implications for the French Citizens’ Convention on Climate.
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Econometrics Seminar
Du 10/05/2021 de 16:00 à 17:15
online
ABADIE Alberto (MIT)
A Penalized Synthetic Control Estimator for Disaggregated Data
écrit avec Co-author: Jérémy L'Hour
Synthetic control methods are commonly applied in empirical research to estimate the effects of treatments or interventions on aggregate outcomes. A synthetic control estimator compares the outcome of a treated unit to the outcome of a weighted average of untreated units that best resembles the characteristics of the treated unit before the intervention. When disaggregated data are available, constructing separate synthetic controls for each treated unit may help avoid interpolation biases. However, the problem of finding a synthetic control that best reproduces the characteristics of a treated unit may not have a unique solution. Multiplicity of solutions is a particularly daunting challenge when the data includes many treated and untreated units. To address this challenge, we propose a synthetic control estimator that penalizes the pairwise discrepancies between the characteristics of the treated units and the characteristics of the units that contribute to their synthetic controls. The penalization parameter trades off pairwise matching discrepancies with respect to the characteristics of each unit in the synthetic control against matching discrepancies with respect to the characteristics of the synthetic control unit as a whole. We study the properties of this estimator and propose data-driven choices of the penalization parameter.
Régulation et Environnement
Du 10/05/2021 de 12:00 à 13:15
online
GOMES Joseph Flavian (Economics School of Louvain and the Institute of Economic and Social Research (IRES))
Regulating Platform Fees under Price Parity
écrit avec Co-author : Andrea Mantovani
Online marketplaces, such as Amazon, or online travel agencies, such as Booking.com, greatly expand consumer information about market offers, but also raise sellers’ marginal costs by charging high commissions. To prevent show-rooming, platforms adopted price parity clauses, which restrict sellers’ ability to offer lower prices in alternative sales channels. Whether to uphold, reform, or ban price parity has been at the center of the policy debate, but so far little consensus has emerged. In this paper, we investigate a natural alternative to lifting price parity; namely, we study how to optimally cap platforms’ commissions. The optimal cap reflects the Pigouvian precept according to which the platform should not charge fees greater than the externality that its presence generates on other market participants. Employing techniques from extreme-value theory, we are able to express the optimal cap in terms of observable quantities. In an application to online travel agencies, we find that current average fees are welfare increasing only if platforms at least double consumers’ consideration sets (relative to alternative ways of gathering information online). This suggests that, in some markets, regulation capping commissions should bind if optimally set.
Paris Game Theory Seminar
Du 10/05/2021 de 11:00 à 12:00
online
DEMEZE-JOUATSA Ghislain-Herman (Bielefeld University)
Repetition and cooperation: a model of finitely repeated games with objective ambiguity
We present a model of repeated games in which players can strategically make use of objective ambiguity. In each round of the repeated game, in addition to the classic pure and mixed actions, players can employ objectively ambiguous actions by using imprecise probabilistic devices such as Ellsberg urns to conceal their intentions. We find that adding an infinitesimal level of ambiguity can be enough to approximate collusive payoffs via subgame perfect equilibrium strategies of the finitely repeated game. Our main theorem states that if each player has many continuation equilibrium payoffs in ambiguous actions, any feasible payoff vector of the original stage-game that dominates the mixed strategy maxmin payoff vector is both ex-ante and ex-post approachable by means of subgame perfect equilibrium strategies of the finitely repeated game with discounting. Our condition is also necessary.