The present paper analyzes situations in which groups compete for rents. A major result in the literature has been that there are both cases where larger groups have advantages and cases where they have disadvantages. The paper provides two intuitive criteria which for groups with homogenous...

This paper surveys some of the strategic aspects that emerge if players fight in an alliance against an enemy. The survey includes the free-rider problem and the hold-up problem that emerges in the baseline model, the role of supermodularity in alliance members' effort contributions, the role of...

This paper shows that peer pressure may lead to dynamic convergence to a norm that is skewed with respect to preferences in society, yet is endogenously upheld by the population. Moreover, a skewed norm will often be more sustainable than a representative norm. This may explain the skewness of...

In experiments, people behave more cooperatively when they are aware of an external threat, while in the field, we observe surprisingly high levels of within - group cooperation in conflict situations such as civil wars. We provide an explanation for these phenomena. We introduce a model in...

Economists commonly use the Edgeworth box to illustrate the ability of exchange to generate gains from trade. In contrast to this framework of dyadic exchange, we explore triadic forms of exchange where margins of coercion are also present. In the presence of triadic exchange, market...

Democratic societies are challenged by various violent and organized groups, be they terrorists, gangs or organized hooligans. In exchange for offering an identity, leaders in such groups typically require members to be violent. We introduce a simple model to capture these stylized facts, and...

We interpret the social identity literature and examine its economic implications. We model a population of agents from two exogenous and well defined social groups. Agents are randomly matched to play a reduced form bargaining game. We show that this struggle for resources drives a conflict...