This paper introduces a new solution concept, a minimax regret equilibrium, which allows for the possibility that players are uncertain about the rationality and conjectures of their opponents. We provide several applications of our concept. In particular, we consider price-setting environments...

A decision maker (DM) makes choices from different sets of alternatives. The DM is initially fully ignorant of the payoff associated to each alternative, and learns these payoffs only after a large number of choices have been made. We show that, in the presence of an outside option once payoffs...

We study the potential evolutionary appeal of rationality in a model in which different populations differ with respect to their experimentation over rules of behavior. We show that more risky experimentation in the sense of mean preserving spread dominates less risky experimentation....