We study communication in ambiguous environments. Agents communicate individual decisions sequentially. Based on the signal that an agent receives, she revises her private information. When signals are ambiguous, we show that agents may agree to disagree forever. Although the learning process...

We introduce a solution concept for signaling games, called Rational Hypothesis Testing Equilibrium (HTE). Beliefs are updated via Ortoleva’s (2012) Hypothesis Testing model, allowing for conditioning on information sets off the path. Hypotheses are beliefs about rational strategies of the...

We observe that a symmetric two-player zero-sum game has a pure strategy equilibrium if and only if it is not a generalized rock-paper-scissors matrix. Moreover, we show that every finite symmetric quasiconcave two-player zero-sum game has a pure equilibrium. Further sufficient conditions for...

We show that for many classes of symmetric two-player games, the simple decision rule "imitate if-better'' can hardly be beaten by any strategy. We provide necessary and sufficient conditions for imitation to be unbeatable in the sense that there is no strategy that can exploit imitation as a...

We show that in symmetric two-player exact potential games, the simple decision rule "imitate-if-better" cannot be beaten by any strategy in a repeated game by more than the maximal payoff difference of the one-period game. Our results apply to many interesting games including examples like 2x2...