The Role of Race in Forecasts of Violent Crime∗

This paper addresses the role of race in forecasts of failure on probation or parole. Failure is defined as committing a homicide or attempted homicide or being the victim of a homicide or an attempted homicide. These are very rare events in the population of individuals studied, which can make these outcomes extremely difficult to forecast accurately. Building in the relative costs of false positives and false negatives, machine learning procedures are applied to construct useful forecasts. The central question addressed is what role race should play as a predictor when as an empirical matter the majority of perpetrators and victims are young, African-American, males.