Heterogeneous causal effects of neighbourhood policing in New York City with staggered adoption of the policy
研究了2015-2018年纽约市各警区逐步推行社区警务的效果，发现该政策减少了部分地区的自由裁量逮捕，但对犯罪率或逮捕中的种族差异影响不大。
Abstract In New York City, neighbourhood policing was adopted at the police precinct level over the years 2015–2018, and it is of interest to both (1) evaluate the impact of the policy, and (2) understand what types of communities are most impacted by the policy, raising questions of heterogeneous treatment effects. We develop novel statistical approaches that are robust to unmeasured confounding bias to study the causal effect of policies implemented at the community level. We find that neighbourhood policing decreases discretionary arrests in certain areas of the city, but has little effect on crime or racial disparities in arrest rates.