Gangs govern millions worldwide. Why rule? And how do they respond to states? Many argue that criminal rule provides protection when states do not, and that increasing state services could crowd gangs out. We began by interviewing leaders from 30 criminal groups in Medellin. The conventional...

As in many cities, gangs in Medellín provide order and collect 'taxes'. Why do gangs govern civilians? Some argue that criminal and state rule are substitutes. Hence, increasing state presence should crowd out gangs. But they could also be complements. States produce growth and general demand...

Using the case of the cocaine trade in Mexico as a relevant and salient example, this paper shows that scarcity leads to violence in markets without third party enforcement. We construct a model in which supply shortages increase total revenue when demand is inelastic. If property rights over...

This paper explores if scarcity increases violence in markets without a centralized authority. We construct a model in which, by raising prices and revenues, temporal supply shortages foster violence. Guided by our model, we examine empirically the link between scarcity and violence in the...