Games and Economic Behavior
Опубликовано на портале: 25-11-2004David Myatt, Chris C. Wallace Games and Economic Behavior. 2004. Vol. 48. No. 1. P. 124-138.
Equilibrium selection in coordination games has generated a large literature. Kandori, Mailath and Rob (1993) and Young (1993) studied dynamic models of aggregate behaviour in which agents choose best responses to observations of population play. Crucially, infrequent mistakes (`mutations`) allow agents to take actions contrary to current trends and prevent initial configurations from determining long run play. An alternative approach is offered here: Harsanyian trembles are added to agents` payoffs so that with some probability it is optimal to act against the flow of play. The long run distribution of population behaviour is characterised - modes correspond to stable Bayesian Nash equilibria. Allowing the variance of payoff trembles to vanish, via a purification process, a single equilibrium is played almost always in the long run. Kandori et al and Young show that the number of contrarian actions required to escape an equilibrium determines selection; here, the likelihood that such actions are taken is of equal importance.
Learning to Play Bayesian Games [статья]
Опубликовано на портале: 14-02-2005Eddie Dekel, Drew Fudenberg, David Knudsen Levine Games and Economic Behavior. 2004. Vol. 46. No. 2. P. 282-303.
This paper discusses the implications of learning theory for the analysis of games with a move by Nature. One goal is to illuminate the issues that arise when modeling situations where players are learning about the distribution of Nature's move as well as learning about the opponents' strategies. A second goal is to argue that quite restrictive assumptions are necessary to justify the concept of Nash equilibrium without a common prior as a steady state of a learning process.