Police Officer on the Frontline or a Soldier? The Effect of Police Militarization on Crime
研究美国地方警察从五角大楼获取的军事装备对犯罪率的影响，发现军事援助减少了街头犯罪且成本有效，支持威慑机制。
Sparked by high-profile confrontations between police and citizens in Ferguson, Missouri, and elsewhere, many commentators have criticized the excessive militarization of law enforcement. We investigate whether surplus military-grade equipment acquired by local police departments from the Pentagon has an effect on crime rates. We use temporal variations in US military expenditure and between-counties variation in the odds of receiving a positive amount of military aid to identify the causal effect of militarized policing on crime. We find that (i) military aid reduces street-level crime; (ii) the program is cost-effective; and (iii) there is evidence in favor of a deterrence mechanism.