This note characterizes the impact of adding rare stochastic muta- tions to an "imitation dynamic," meaning a process with the properties that any state where all agents use the same strategy is absorbing, and all other states are transient. The work of Freidlin and Wentzell [10] and its...

Consider a model of location choice by two sorts of agents, called “buyers”and “sellers:”In the first period agents simultaneously choose between two identical possible locations; following this, the agents at each location play some sort of game with the other agents there. Buyers...

better understand when mixed equilibria might arise within populations of interact acting agents, we examine a model of smoothed fictitious play that is designed to capture Harsanyi's "Purification", view of mixed equilibria in a setting with a large population of agents. Our analysis concerns...

We define and analyze "strategic topologies" on types, under which two types are close if their strategic behavior will be similar in all strategic situations. To oper- ationalize this idea, we adopt interim rationalizability as our solution concept, and define a metric topology on types in the...

We propose that a simple “dual-self” model gives a unified explanation for several empirical regularities, including the apparent time-inconsistency that has motivated models of hyperbolic discounting and Rabin’s paradox of risk aversion in the large and small. The model also implies that...

This paper studies the conditions under which two competing and otherwise identical markets or auction sites of different sizes can coexist in equilibrium, without the larger one attracting all of the smaller one’s patrons. We find that the range of equilibrium market sizes depends on the...

We propose that a simple “dual-self” model gives a unified explanation for several empirical regularities, including the apparent time-inconsistency that has motivated models of hyperbolic discounting and Rabin’s paradox of risk aversion in the large and small. The model also implies that...

In traditional reputation theory, reputation is good for the long-run player. In “Bad Reputation,” Ely and Valimaki give an example in which reputation is unambiguously bad. This paper characterizes a more general class of games in which that insight holds, and presents some examples to...

The code of Hammurabi specified a “trial by surviving in the river” as a way of deciding whether an accusation was true. This system is puzzling for two reasons. First, it is based on a superstition: We do not believe that the guilty are any more likely to drown than the innocent. Second, if...

We show the existence of a pure strategy, symmetric, increasing equilibrium in double auction markets with correlated private valuations and many participants. The equilibrium we find is arbitrarily close to fully revealing as the market size grows. Our results provide strategic foundations for...