Peer Effects in Police Use of Force
研究利用警察学院随机分班形成的同伴网络，发现警察因公受伤后，其同伴在接下来一周使用武力的概率增加7%，且更可能伤害嫌疑人、收到投诉，表明情绪反应而非社会学习驱动该效应。
We study the link between police officers’ on-duty injuries and their peers’ force use using a network of officers who attended the police academy together through a random lottery. On-duty injuries increase the probability of officers using force by 7 percent in the subsequent week. Officers are also more likely to injure suspects and receive complaints about neglecting victims and violating constitutional rights. The effect is concentrated in a narrow time window following the event and is not associated with significantly lower injury risk to the officer. Together, these findings suggest that emotional responses drive the effects rather than social learning.