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...

In this paper I advance an explanation of the social origins of cocaine trafficking in Colombia in which two thresholds are distinguish. The first threshold occurs when the knowledge and the willingness for a specific criminal activity reproduce faster than the enforcement capacity of the...