In a two-person ¯nitely repeated public goods experiment, we use intentions data to interpret individual behavior. Based on a random-utility model speci¯cation, we develop a relationship between a player's beliefs about others' behavior and his contributions' plans, and use this relationship...

We study conditional cooperation based on a sequential two-person linear public good game in which a trusting first contributor can be exploited by a second contributor. After playing this game the first contributor is allowed to punish the second contributor. The consequences of sanctioning...

Strategy changes are an essential part of evolutionary games. Here we introduce a simple rule that, depending on the value of a single parameter w, influences the selection of players that are considered as potential sources of the new strategy. For positive w players with high payoffs will be...

In a world in which many pressing global issues require large scale cooperation, understanding the group size effect on cooperative behavior is a topic of central importance. Yet, the nature of this effect remains largely unknown, with lab experiments insisting that it is either positive or...

In the last few decades, numerous experiments have shown that humans do not always behave so as to maximize their material payoff. Cooperative behavior when non-cooperation is a dominant strategy (with respect to the material payoffs) is particularly puzzling. Here we propose a novel approach to...

We study the evolution of cooperation under the assumption that the collective benefits of group membership can only be harvested if the fraction of cooperators within the group, i.e., their critical mass, exceeds a threshold value. Considering structured populations, we show that a moderate...

There are many situations where the best outcome is reached through co-operation and co-ordination of agents’ actions. Although this is the best collective outcome, economic agents may fail to implement such co-operative strategy. The reason for this failure may be lack of information about...

We study conditional cooperation based on a sequential two-person linear public good game in which a trusting first contributor can be exploited by a second contributor. After playing this game the first contributor is allowed to punish the second contributor. The consequences of sanctioning...

Until recently, theorists considering the evolution of human cooperation have paid little attention to institutional punishment, a defining feature of large-scale human societies. Compared to individually-administered punishment, institutional punishment offers a unique potential advantage: the...

The conflict between pro-self and pro-social behaviour is at the core of many key problems of our time, as, for example, the reduction of air pollution and the redistribution of scarce resources. For the well-being of our societies, it is thus crucial to find mechanisms to promote pro-social...