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...

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...

We examine how globalization affects trade patterns and welfare when conflict prevails domestically. We do so in a simple model of trade, in which a natural resource like oil is contested by competing groups using real resources (?guns?). Thus, conflict is viewed as ultimately stemming from...

We examine a stark setting in which security or protection can be provided by self-governing groups or by for-profit entrepreneurs (kings, kleptocrats, or mafia dons). Though selfgovernance is best for the population, it faces problems of long-term viability. Typically, in providing security the...