The Influence of Driver's Race on Traffic Stops in Missouri

A small but growing body of research has produced several consistent findings regarding race and ethnic differences in traffic stops, searches, and arrests. However, prior research has not adequately addressed the potential bias associated with the use of residential population data to estimate the racial composition of the drivers in local areas. The authors present a new method of imputing the racial composition of drivers in a given locality based on the size and composition of nearby areas. Applying the method to traffic-stop data for 92 Missouri municipalities, the authors produce more accurate estimates than those based on residential population data of racial disproportionality in traffic stops for several suburban areas surrounding the city of St. Louis. Nonetheless, they find small but persistent group differences in the probability of being pulled over by the police for the 92 municipalities and larger differences in the probability of being searched and arrested.