Séminaires LEMMA

''Short term effects of the Indian Demonetization"
Carla Canelas – American University of Paris et Centre d’économie de la Sorbonne 
Mardi 6 décembre 2022 - 11 h / 12 h
Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas

Abstract :
In November  2016, the Indian Government  announced the sudden demonetization of 86 per cent  of India’s cash in circulation.  We exploit the geographical variation of the banking system across Indian districts and the timing of the announcement of the policy, to implement a difference-in-differences approach and study the effects of the 2016  Indian demonetization on individual and household outcomes. In particular, the paper  analyses the short term effects of the policy on employment, household income and consumption, as well as savings and borrowing.  The results show a significant heterogeneity in the impact across households in different income quantiles and across  individuals in different occupations.


''Empirical welfare economics"
Federico Echenique - UC Berkeley
Mardi 22 novembre 2022 - 11 h / 12 h
Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas

Abstract :
Welfare economics relies on access to agents’ utility functions: we revisit classical questions in welfare economics, assuming access to data on agents’ past choices instead of their utilities. Our main result considers the existence of utilities that render a given allocation Pareto optimal. We show that a candidate allocation is efficient for some utilities consistent with the choice data if and only if it is efficient for an incomplete relation derived from the revealed preference relations and convexity. Similar ideas are used to make counterfactual choices for a single consumer, policy comparisons by the Kaldor criterion, and determining which allocations, and which prices, may be part of a Walrasian equilibrium.


''Sequential Equilibria in a Class of Infinite Extensive Form Games"
Michael Greinecker - ENS Paris-Saclay
(en collaboration avec Martin Meier and Konrad Podczeck)
Mardi 08 novembre 2022 - 11 h / 12 h
Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas

Abstract :
Sequential equilibrium is one of the most fundamental refinements of Nash equilibrium for games in extensive form but is only defined for finite extensive-form games and is inapplicable whenever a player can choose among a continuum of actions. We define a class of infinite extensive form games in which information behaves continuously as a function of past actions and define a natural notion of sequential equilibrium for this class. Sequential equilibria exist in this class and refine Nash equilibria. In finite extensive-form games, our definition selects the same strategy profiles as the traditional notion of a sequential equilibrium.


"Silent Spreaders: Behavior and Equilibrium Under Asymptomatic Infection"
Flavio Toxvaerd  - Université de Cambridge
Mardi 25 octobre 2022 - 10 h / 11 h

Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas

Abstract :  
This paper analyzes equilibrium social distancing choices in a model with potentially asymptomatic infection. Since infection only prompts symptoms probabilistically, individuals cannot perfectly infer their health state from the absence of symptoms. Instead, they must form beliefs about their health state based on knowledge of the population frequencies. I show that relative to a benchmark with perfect health state information, asymptomatic infection leads to lower mitigation through four distinct channels, some mechanistic and some that work through beliefs and thus decisions. The model is then applied to an analysis of individual and mass testing. The value of the former derives from the value of information and it is shown that the latter may influence the course of the epidemic through its influence on aggregate equilibrium behavior. Tests for immunity generally have a higher value of information and aggregate effects than tests for infection.


"Do Elections Affect Immigration? Evidence from French Municipalities"
Grégory Verdugo - Université d’Evry

Mardi 18 octobre 2022 - 11 h / 12 h
Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas