Judges, Juveniles, and In-Group Bias
利用美国某州1996-2012年青少年法庭案件数据及法官随机分配，发现法官对同种族青少年存在负面内群体偏见，表现为更可能判处监禁而非缓刑且刑期更长。
We investigate the existence of in-group bias (preferential treatment of one’s own group) in court decisions. Using the universe of juvenile-court cases in a US state between 1996 and 2012 and exploiting random assignment of juvenile defendants to judges, we find evidence for negative racial in-group bias in judicial decisions. All else being equal, black (white) juveniles who are randomly assigned to black (white) judges are more likely to be placed in custody, as opposed to being placed on probation, and they receive longer sentences. Although observed in experimental settings, this is the first empirical evidence of negative in-group bias based on a randomization design outside the lab. We provide explanations for this finding.