Blackwell's Comparison of Experiments and Discounted Repeated Games (Job Talk)
Joint work with Ehud Lehrer
Among the hardest long lasting questions in Game Theory is the characterization of the set of equilibrium payoffs when the signals observed by the players are noisy (models of repeated games with private monitoring). One of the challenges is detecting deviations from the equilibrium. We consider a model where each player observes only his own payoffs. We use the partial order over information structures introduced by Blackwell. When adapted to the framework of repeated games, this order draws a clear line between detectable and undetectable deviations. Combining with former results (regarding the richness of the span of the information matrix of the minmax strategy) we obtain a full characterization of the equilibrium payoffs.