The Thin (Red) Blue Line: Police Militarization and Violent Crime

Recent events such as the riots in Ferguson, Missouri, have highlighted the increased militarization of police forces in the United States. This paper utilizes a new dataset that covers all military equipment transfers between the Defense Logistics Agency and local police forces from 1990 to 2014 to consider the effect of increased militarization on crime. These transactions were conducted under the Department of Defense’s 1033 Program and constitute a major transfer of capital resources to local police departments with nearly two billion dollars transferred in the form of surplus military equipment. To deal with concerns of identification, we instrument for participation in the 1033 program using state-level exposure to the military through federal military spending set by Congress. We find that increased capital transfers to states embodied in military equipment reduces total violent crime and violent crime subcategories. The effect is large for overtly militaristic equipment such as assault rifles, but also for less militaristic transfers such as communication equipment, implying that both enhanced capabilities as well as power projection are important drivers of violent crime reduction. In addition, we find no evidence of a labor input response through additional hiring of sworn police officers, indicating that the program resulted in a more capital-intensive police force. Further, we find that increased police militarization results in lower incarceration rates even after controlling for reduced crime rates, suggesting a broader law and order impact beyond just enhanced capabilities. The results make clear that increased police militarization in the United States has played a meaningful role in the reduction in violent crime observed over the last twenty-five years.