Consent searches: Evaluating the usefulness of a common and highly discretionary police practice

We analyze the consequences of using driver consent as a basis for initializing a traffic stop-and-search compared to those searches based on probable cause. We find that consent searches are less likely to result in contraband recovery than are probable cause searches. Moreover, police agencies with a relatively higher reliance on consent searches find similar amounts of contraband and make a similar number of arrests as agencies doing much less searching but with a greater reliance on probable cause. These patterns are amplified along racial lines, and there is no discernible relationship between the use of consent searches and crime. We also provide causal evidence that corroborate these observational findings by examining the consequences of a Texas Highway Patrol policy, which suddenly increased the consent search rate in two South Texas counties. We show the contraband recovery rate discontinuously decreases when the consent search rate discontinuously increases.