https://hal-hec.archives-ouvertes.fr/hal-00539148Scarsini, MarcoMarcoScarsiniGREGH - Groupement de Recherche et d'Etudes en Gestion à HEC - HEC Paris - Ecole des Hautes Etudes Commerciales - CNRS - Centre National de la Recherche Scientifiquedipartimento di Statistica e Matematica - Université de TurinRenault, JeromeJeromeRenaultCEREMADE - CEntre de REcherches en MAthématiques de la DEcision - Université Paris Dauphine-PSL - PSL - Université Paris sciences et lettres - CNRS - Centre National de la Recherche ScientifiqueUniversité Paris Dauphine-PSL - PSL - Université Paris sciences et lettresScarlatti, SergioSergioScarlattiA folk theorem for minority gamesHAL CCSD2005Repeated gamesImperfect monitoringPublic signals[MATH] Mathematics [math]Haldemann, Antoine2010-11-24 10:39:112022-06-25 10:51:302010-11-24 10:39:11enJournal articles10.1016/j.geb.2004.09.0131We study a particular case of repeated games with public signals. In the stage game an odd number of players have to choose simultaneously one of two rooms. The players who choose the less crowded room receive a reward of one euro (whence the name “minority game”). The players in the same room do not recognize each other, and between the stages only the current majority room is publicly announced. We show that in the infinitely repeated game any feasible payoff can be achieved as a uniform equilibrium payoff, and as an almost sure equilibrium payoff. In particular we construct an inefficient equilibrium where, with probability one, all players choose the same room at almost all stages. This equilibrium is sustained by punishment phases which use, in an unusual way, the pure actions that were played before the start of the punishment.