A new study, about to be published in the Journal of Legal Studies, finds that racial bias affects judicial sentencing decisions. The study, entitled “Do Judges Vary in Their Treatment of Race?” was authored by David S. Abrams of the University of Pennsylvania School of Law, Marianne Bertrand of the University of Chicago, and Sendhil Mullainathan of Harvard University.
Looking at a huge database of criminal cases in Cook County, Illinois, the authors looked at the sentences given Black and White defendants by particular judges. Since cases are randomly assigned, the authors state “if you have a large enough sample of cases, on average across judges they’re going to get the same types of cases, meaning the same mix of race of the defendant, the same mix of crimes. Everything about the cases, assuming they’re randomly assigned, should be the same on average for each judge, including the variables we can’t observe.”
For all cases, the authors found a mean incarceration rate of 51 percent for Blacks and 38 percent for Whites. But controlling for variables, the authors found that there is a significant racial gap in incarceration rates between judges that increases the racial gap by as much as 18 percentage points.
The paper can be accessed here.