The Contagion of Drug Violence

Why are some territories ravaged by intense levels of criminal violence while others are relatively peaceful? This research contributes to an understanding of the escalation and diffusion of drug violence in Mexico from 2000 to 2010 by formalizing the interactions between the state and organized criminals and by relying on a large database of event data containing more than 1.6 million observations. Results based on spatial econometrics provide evidence of the spatial diffusion of violence. In congruence with the theoretical expectations, the results show that the disruptive effect of law enforcement is an important catalyst for the intensification of violence between criminal organizations, especially when deployed in areas hosting a high concentration of criminal groups. This relationship holds for a broad menu of violent and nonviolent law enforcement tactics. The analysis also reveals that other broadly held factors (international, geographic, and socioeconomic characteristics) have a modest effect on the dynamics of drug-related violence.