Bringing War Home: Violent Crime, Police Killings and the Overmilitarization of the US Police

The withdrawal from the Afghan and Iraqi wars has led to the arrival of vast quantities of military equipment to the US. Much of this equipment, now unused by the military, has been redistributed to police departments via a program called 1033. In this paper, I study the causal effect on criminal activity and police behavior of the militarization of the police through this program. I do so by taking into account that military equipment is stored in various disposition centers. Police departments do not pay for the cost of these items but must cover all transportation costs. I then use the distance to a disposition center and the timing of the US withdrawal from the wars in an instrumental variable setting. Estimates show that military equipment reduces violent crime and is responsible for 60% of the rapid drop observed since 2007. More than one third of this effect is caused by the displacement of violent crime to neighboring areas. Because police departments do not consider this externality when making militarization decisions, they overmilitarize. Finally, I show that police militarization increases the number of people killed by the police. Estimates imply that all the recent increases in police killings are due to police militarization.