Contests between groups are plagued by intra-group externalities (freeriding). Yet, costless incentive schemes that entirely avoid free-riding within a group might not be desirable, neither individually nor socially. In contests among two groups, a relatively weak (i.e., small or unproductive)...

I critically review recent studies that estimate those costs of violence and conflict that can emerge among organized political groupings, from states, religious and ethnic organizations to guerillas and paramilitaries. The review includes studies that estimate direct and indirect costs due to...

Wars of conquest and wars of independence are characterized by an asymmetric payoff structure: one party gets aggregate production if it wins, and its own production if it loses, while the other party gets only its own production if it wins, and nothing if it loses. We study a model of war with...

We show that the recent rise in Afghan opium production is caused by violent conflicts. Violence destroys roads and irrigation, crucial to alternative crops, and weakens local incentives to rebuild infrastructure and enforce law and order. Exploiting a unique data set, we show that Western...

We develop a theory of interstate conflict in which the degree of genealogical relatedness between populations has a positive effect on their conflict propensities because more closely related populations, on average, tend to interact more and develop more disputes over sets of common issues. We...

This paper examines conflicts in which performance is measured by the players' success or failure in multiple component conflicts, commonly termed “battlefields”. In multi-battlefield conflicts, behavioral linkages across battlefields depend both on the technologies of conflict within each...

We augment the canonical neoclassical model of trade to allow for interstate disputes over land, oil, water, or other resources. The costs of such disputes in terms of arming depend on the trade regime in place. Under either autarky or free trade, the larger country (in terms of factor...

In this paper we examine a model of terrorism which focuses on the tradeoffs facing a terrorist organization that has the ability to utilize either or both suicide and conventional terrorism tactics. The terrorist organization’s objective is to successfully attack at least one target. Success...

This article investigates the impact of the distribution of preferences on equilibrium behavior in conflicts that are modeled as all-pay auctions with identity-dependent externalities. In this context, we define centrists and radicals using a willingness-to-pay criterion that admits preferences...

We study the role of inter-group differences in the emergence of conflict. In our setting, two groups compete for the right to allocate societys resources, and we allow for costly intergroup mobility. The winning group offers an allocation, that the opposition can either accept, or reject and...