Using an identification strategy based on random assignment of refugees to different municipalities in Denmark between 1986 and 1998, we find strong evidence that gang crime rates in the neighbourhood at assignment increase the probability of boys to commit crimes before the age of 19, and that...

Delinquents are embedded in a network of relationships. Social ties among delinquents are modeled by means of a graph where delinquents compete for a booty and benefit from local interactions with their neighbors. Each delinquent decides in a non-cooperative way how much delinquency effort he...