The importance of categorical reasoning in human cognition is well-established in psychology and cognitive science, and it is generally acknowledged that one of the most important functions of categorization is to facilitate prediction. This paper provides a model of optimal categorization. In...

The importance of categorical reasoning in human cognition is well-established in psychology and cognitive science, and it is generally acknowledged that one of the most important functions of categorization is to facilitate prediction. This paper provides a model of optimal categorization. In...

We study environments in which agents are randomly matched to play a Prisoner's Dilemma, and each player observes a few of the partner's past actions against previous opponents. We depart from the existing related literature by allowing a small fraction of the population to be commitment types....

We develop a formal model of social duties. Duties to respect entitlements (duties of justice) differ from duties to promote well-being (duties of charity). A situationspecific version of our model takes entitlements as primitives. A fully portable version derives entitlements from situational...

We propose a new explanation of the endowment effect. The value of exchanged goods is uncertain. Specifically, the value is assumed to be ambiguous, represented by a set of probability distributions over possible values. Ambiguity averse agents (maxmin expected utility maximisers) set WTA and...