Calendrier du 15 décembre 2022
TOM (Théorie, Organisation et Marchés) Lunch Seminar
Du 15/12/2022 de 12:30 à 13:30
Salle R1-14, Campus Jourdan, 75014 Paris
FRIEDMAN Evan (PSE)
*QRE with a continuum of types.
Quantal response equilibrium (QRE), a statistical generalization of Nash equilibrium, is a standard benchmark in the anlaysis of experimental data. A QRE is a solution to a non-polynomial system of equations, and so does not have a closed-form expression. For this reason, applications rely on numerical methods, and theoretical results are limited. An insight of recent work on finite games is that, whereas it is difficult to solve for any given QRE, it is often easy to characterize the set of all QRE that satisfy a regularity condition. This non-parametric QRE analysis implies novel bounds on the common parametric models and opens up the possibility for novel theoretical applications. This analysis, however, simply does not apply to infinite games. In this paper, we identify a class of infinite games–those with binary actions and a continuum of types–for which non-parametric QRE analysis is feasible. We derive characterization results and apply them to several classic games.
Travail et économie publique externe
Du 15/12/2022 de 12:30 à 13:30
PSE- 48 boulevard Jourdan, 74014 Paris, salle R1-13
MONRAS Joan (Barcelona School of Economics)
Floating population: consumption and location choices of rural migrants in China
écrit avec Imbert, Seror and Zylberberg
This paper provides new theory and evidence on how the consumption patterns of the ``floating population'' of rural migrants affect the distribution of activity across Chinese cities. We first show that: (i) rural migrants sort into cities where wages are high, and rents are also high; (ii) in these cities, they live in poorer housing conditions and without their family; and (iii) they also remit more, especially migrants living without their family. We then develop a quantitative spatial model in which migrants choose whether, how (with or without their family) and where to migrate, and in which they partly consume in their origin location. We estimate the model and compute counterfactual migration flows when local registration restrictions are tightened to make it harder for migrants to settle at destination: there is less migration overall but more in the large, high-wage/high-rents cities.
Behavior seminar
Du 15/12/2022 de 11:00 à 12:00
R1-13
PRATI Alberto (University College London)
*Why do beliefs diverge? Evidence from a natural experiment on COVID-19 vaccines
During the COVID-19 pandemic, UK residents could choose to opt into the vaccination program, but not which vaccine they received. Using this natural experiment, we investigate individuals' beliefs about COVID-19 vaccines before and after vaccination. Although the majority of people were expecting a type of vaccine (Pfizer), about 20% of them were assigned to another one (Moderna). We study how people who received Moderna (treatment group) updated their beliefs differently from those who received Pfizer (control group). We document three results. First, individuals overly optimistically updated their beliefs about the safety and effectiveness of the vaccine they received, so that the average beliefs of the control and treatment groups diverge. Second, we show that this divergence is driven by those who were particularly skeptical about a vaccine but then were assigned to it, and those who were particularly keen on a vaccine but then did not receive it. Third, we find that people adapt not only their beliefs, but also their preferences: the desirability of a vaccine adjusted according to which vaccine people received. These findings shed light on the predictable nature of individuals' beliefs in the field, and are in line with a dynamic of wishful beliefs updating. They suggest that wishful thinking can cause beliefs divergence, even when similar individuals are exposed to similar information environments, hold similar priors, and have no room for ex-post rationalization of previous decisions.
Macroeconomics Seminar
Du 15/12/2022