Body‐worn cameras, police arrests, and bureaucratic discretion: A large‐scale causal analysis across the United States
利用美国697个地方警察机构12年的面板数据，采用交错双重差分法，发现佩戴随身摄像头使黑人逮捕减少约5.5%（集中在酒驾等自由裁量权大的案件），但白人涉武器逮捕增加7.7%。
Abstract Drawing on the literature on bureaucratic discretion, this study conducts a large‐scale, nationwide causal analysis of the effects of body‐worn cameras (BWC) in the United States (US). It employs a staggered difference‐in‐differences (DiD) approach using 12 years of panel data (2008–2019) covering 697 local police agencies. The findings indicate that BWC adoption had no significant effect on White arrests but led to an approximately 5.5% decrease in Black arrests. Importantly, the reduction in Black arrests was concentrated in alcohol‐related cases, which involve considerable officer discretion, but did not extend to cases categorized as more serious public safety threats, such as violent or property crimes, where officer discretion may be more limited. Meanwhile, there was also a 7.7% increase in White arrests related to weapon offenses, aligning with prior studies that suggest BWCs may serve as a tool for evidence collection. Our findings provide insight into how BWCs have influenced police arrests in the US, advancing beyond previous single‐case evaluations.