Fair Profiling

There are several strategies available to police “stopping” suspects. Most efficient is to stop only members of the group with the highest a priori probability of guilt; least efficient is indiscriminate stopping. An efficient option that satisfies one criterion for fairness is a strategy that matches stop probability to risk probability. But a strategy that chooses stop probabilities so that the absolute number of innocents stopped is equal for all groups is close to maximally efficient and seems fair by almost any criterion.