Do Judges Vary in Their Treatment of Race?
利用随机分配案件给法官的机制，测量法官之间在监禁率和刑期上对非裔与白人被告的差异，发现监禁率存在显著差异但刑期无。
Are minorities treated differently by the legal system? Systematic racial differences in case characteristics, many unobservable, make this a difficult question to answer directly. In this paper, we estimate whether judges differ from each other in how they sentence minorities, avoiding potential bias from unobservable case characteristics by exploiting the random assignment of cases to judges. We measure the between-judge variation in the difference in incarceration rates and sentence lengths between African American and white defendants. We perform a Monte Carlo simulation in order to explicitly construct the appropriate counterfactual, in which race does not influence judicial sentencing. In our data set, which includes felony cases from Cook County, Illinois, we find statistically significant between-judge variation in incarceration rates, although not in sentence lengths.