Racial Bias in Motor Vehicle Searches: Additional Theory and Evidence

Knowles, Persico, and Todd (2001) develop a model of police search and offender behavior. Their model implies that if police are unprejudiced the rate of guilt should not vary across groups. Using data from Interstate 95 in Maryland, they find equal guilt rates for African-Americans and whites and conclude that the data is not consistent with racial prejudice against African-Americans. This paper generalizes the model of Knowles, Persico, and Todd by accounting for the fact that potential offenders are frequently not observed by the police and by including two different levels of offense severity. The paper shows that for African-American males the data is consistent with prejudice against African-American males, no prejudice, and reverse discrimination depending on the form of equilibria that exists in the economy. Additional analyses based on stratification by type of vehicle and time of day were conducted, but did not shed any light on the form of equilibria that best represents the situation in Maryland during the sample period.

For Sale: Trade Policy in Majoritarian Systems

We provide a theory of trade policy determination that incorporates the protectionist bias inherent in majoritarian systems, suggested by Grossman and Helpman (2005). The prediction that emerges is that in majoritarian systems, the majority party favors industries located disproportionately in majority districts. We test this prediction using U.S. tariff data from 1993, and House campaign contribution data from two electoral cycles. We find evidence of a protectionist bias due to majoritarian system politics that is comparable in magnitude to the payoff from being an organized industry.