Predictive Bias and Disparate Impact Jennifer

* The views expressed in this article are those of the authors alone and do not reflect the official position of the Administrative Office of the U.S. Courts. Lowenkamp specifically advises against using the PCRA to inform front-end sentencing decisions or back-end decisions about release without first conducting research on its use in these contexts, given that the PCRA was not designed for those purposes. Abstract One way to unwind mass incarceration without compromising public safety is to use risk assessment instruments in sentencing and corrections. These instruments figure prominently in current reforms, but controversy has begun to swirl around their use. The principal concern is that benefits in crime control will be offset by costs in social justice—a disparate and adverse effect on racial minorities and the poor. Based on a sample of 34,794 federal offenders, we empirically examine the relationships among race (Black vs. White), actuarial risk assessment (the Post Conviction Risk Assessment [PCRA]), and re-arrest (for any/violent crime). First, application of well-established principles of psychological science revealed no real evidence of test bias for the PCRA—the instrument strongly predicts re-arrest for both Black and White offenders and a given score has essentially the same meaning-i.e., same probability of recidivism—across groups. Second, Black offenders obtain modestly higher average scores on the PCRA than White offenders (d= .43; appx. 27% non-overlap in groups' scores). So some applications of the PCRA could create disparate impact—which is defined by moral rather than empirical criteria. Third, most (69%) of the racial difference in PCRA scores is attributable to criminal history—which strongly predicts recidivism for both groups and is embedded in sentencing guidelines. Finally, criminal history is not a proxy for race—instead, it fully mediates the otherwise weak relationship between race and re-arrest. Data may be more helpful than rhetoric, if the goal is to improve practice at this opportune moment in history. Over recent years, increased awareness of the economic and human toll of mass incarceration in the U.S. has launched a reform movement in sentencing and corrections (see Lawrence, 2013). This remarkably bipartisan movement (Arnold & Arnold, 2015) is shifting public discourse about criminal justice " away from the question of how best to punish, to how best to achieve long-term public safety " (Subramanian, Moreno, & Broomhead, 2014, p. 2). One way to begin unwinding mass incarceration without compromising public safety is to use risk assessment instruments in sentencing and …