Conflict and cooperation do not result from isolated individual actions. In settings such as
insurgency, interstate conflict, protest mobilization, and informal governance, actors are …

Decades of research using a wide variety of detailed plant-and firm-level data has provided
strong evidence of persistent performance differences among seemingly similar enterprises …

We provide a model of conflict and mass killing decisions to identify the key variables and
situations that make mass killings more likely to occur. We predict that mass killings are most …

While rumors predominate in conflict settings, researchers have not identified whether and
why they influence the start of organized armed conflict. In this paper, we advance a new …

Many communities rely upon ostracism to enforce cooperation: if an individual shirks in one
relationship, her innocent neighbors share information about her guilt in order to shun her …

Which social norms and networks maximize cooperation in bilateral relationships? We study
a network of players in which each link is a repeated bilateral partnership with two-sided …

We propose a simple model of the emergence of equality before the law. A society can
support effort ('cooperation','prosocial behaviour') using the carrot of future cooperation or …

To answer questions about the origins and outcomes of collective action, political scientists
increasingly turn to datasets with social network information culled from online sources …

We examine how trust is sustained in large societies with random matching, when records of
past transgressions are retained for a finite length of time. To incentivize trustworthiness …

We introduce the possibility of coercive punishment by specialized enforcers into a model of
community enforcement. We assume that, just as regular agents need to be given incentives …