Often in cooperative situations, many aspects of the decision-making environment are uncertain. We investigate how cooperation is shaped by the way information about risk is presented (from description or from experience) and by differences in risky environments. Drawing on research from risky...

We investigate the scope for cooperation within a community engaged in repeated reciprocal interactions. Players seek the help of others and approach them sequentially according to some fixed order, that is, a ranking profile. We study the ranking profiles that are most effective in sustaining...

We study the coexistence of strategies in the indirect reciprocity game where agents have access to second-order information. We fully characterize the evolutionary stable equilibria and analyze their comparative statics with respect to the cost-benefit ratio (CBR). There are indeed only two...

Community enforcement is an important device for sustaining efficiency in some repeated games of cooperation. We investigate cooperation when information about players' reputations spreads to their future partners through links in a social network that connects them. We find that information...

This paper examines the role of pro-social behavior as a mechanism for the establishment and maintenance of cooperation in resource use under variable social and environmental conditions. By coupling resource stock dynamics with social dynamics concerning compliance to a social norm prescribing...

We develop a simple model to study the coevolution of interaction structures and action choices in Prisoners' Dilemma games. Agents are boundedly rational and choose both actions and interaction partners via payoff-based imitation. The dynamics of imitation and exclusion yields polymorphic...

If there exist no incentive or selective mechanisms that make cooperation in large groups incentive-compatible under realistic circumstances, functional social institutions will require subjective preferences to diverge from objective payoffs – a "noble lie." This implies the existence of...

We propose a stylised dynamic model to understand the role of social networks in the phenomenon we call "globalization." This term refers to the process by which even agents who are geographically far apart come to interact, thus being able to overcome what would otherwise be a fast saturation...

We investigate the welfare effect of increasing competition in an anonymous two-sided matching market, where matched pairs play an infinitely repeated Prisoner's Dilemma. Higher matching efficiency is usually considered detrimental as it creates stronger incentives for defection. We point out,...

Group tasks are often organized by a list: group members state their willingness to contribute by entering their names on a publicly visible, empty list. Alternatively, one could organize the group task by starting with a full list: every group member is already entered on the list and...