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 discussion paper led to a publication in <A href="http://onlinelibrary.wiley.com/doi/10.1111/1467-9442.00182/abstract">'Journal of Economics'</A> 102(1) 23-39.<P>We compare a partners condition where the same small group of subjects plays arepeated public good game to astrangers condition where subjects play this game in changing group formations.Subjects in the partners...</p></a>

Economic behavior often takes place in groups of small numbers of peopleinteracting with each other (like work teams, neighborhoods, socialnetworks, etc.). Characteristic of such interaction is the development of(affective) interpersonal relationships, or social ties. According tosociologists,...

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...