This discussion paper led to a chapter in: (S.N. Durlauf & L.E. Blume (Eds.))<I>The New Palgrave Dictionary of Economics</I> 2nd ed. Vol.4, pp. 402-406. Basingstoke: Palgrave Macmillan, 2008.<P> Interacting agents in finance represent a behavioral, agent-based approach in which financial markets are...</p></i>

This paper analyses the behavior of an individual who wants to maximize his utility function, but he is not able to evaluate it. There are many ways to choose a single alternative from a given set. We show that a unique utility maximizing procedure exists. Choices induced by this optimal...

The origin of prospect theory is the desire to test the intuitive statistician in the real world. The development of this theory by the cognitive psychologists Kahneman and Tversky can be traced to the formers work in cognitive psychophysics, in which deviations from average behavior are termed...

We show that if an agent is uncertain about the precise form of his utility function, his actual relative risk aversion may depend on wealth even if he knows his utility function lies in the class of constant relative risk aversion (CRRA) utility functions. We illustrate the consequences of this...

Many important decisions are made without precise information about the probabilities of the outcomes. In such situations, individual ambiguity attitudes influence decision making. The present study identifies affective states as a transient cause of ambiguity attitudes. We conducted two...

We consider the possibility that cooperation in a prisoner's dilemma is fostered by people's voluntarily enhancement of their own vulnerability. The vulnerability of a player determines the effectiveness of possible punishment by the other. In the "Gradual" mechanism, players may condition their...

We conduct an experiment to test whether the size of a loss and the time in a losing position affect investors’ adaptation to the loss situation and, subsequently, whether this adaptation affects future investment decisions. As investors adapt to losses, their neutral reference point shifts...

Explaining the evolution and maintenance of cooperation among unrelated individuals is one of the fundamental problems in biology and the social sciences. Recent experimental evidence suggests that altruistic punishment is an important mechanism to maintain cooperation among humans. In this...

<b>Purpose:</b><br>This paper addresses the nature, formalization, and neural bases of (affective) social ties anddiscusses the relevance of ties for health economics. A social tie is defined as an affectiveweight attached by an individual to the well-being of another individual ('utilityinterdependence')....

This paper reviews three distinct strategies in recent economics for using the concept of social identity in the explanation of individual behavior: Akerlof and Kranton’s neoclassical approach, Sen’s commitment approach, and Kirman et al.’s complexity approach. The primary focus is the...