Racial fairness in violence risk instruments: a review of the literature

Violence risk instruments are used in numerous countries to estimate an individual's risk of reoffending. The racial fairness of violence risk instruments has received increasing attention due to ostensible differences among Anglo populations and racial minorities (e.g. African Americans and Indigenous populations). Fairness, which has numerous definitions (sensitivity fairness, error rate balance, calibration, predictive parity, statistical parity), can affect a risk instrument's utility in varying ways. This literature review explored how notions of fairness are discussed in the risk instrument literature with a specific focus on racial fairness. It also examined and critiqued the varying proposed resolutions to increase fairness. Many of these forms of fairness were found to be rarely satisfied in the literature. Further, the complications in achieving multiple forms of fairness simultaneously and the challenges of optimising both fairness and accuracy are discussed. Last, proposed solutions to increase racial fairness were often found to encompass significant limitations. Future directions for racial fairness in risk instruments are discussed, with a focus on exploring the trade-offs among varying fairness definitions and among fairness and accuracy.