We model interaction within the members of a work group, who carry on different projects and can choose to cooperate with each other or to exploit the work of the others. We focus our attention on the dynamic interdependence between their material performance and the structure of the relations...

Behind my reciprocation of a friend's gift may lie both instrumental reasons (I expect further future gifts) and communicative reasons (I want to establish or confirm a friendship per se ). In a theory of rational individual action, such communicative reasons can be incorporated as an argument...

Behind my reciprocation of a friend's gift may lie both instrumental reasons (I expect further future gifts) and 'communicative' reasons (I want to establish or confirm a friendship per se). In a theory of rational individual action, such 'communicative' reasons can be incorporated as an...