Racial Bias in Motor Vehicle Searches: Theory and Evidence
构建了一个模型，分析警察在交通检查中是否因种族差异而区别对待司机，并提出了一个检验方法，用于区分这种差异是出于效率考虑还是种族偏见，最后用马里兰州的数据进行了实证检验。
African American motorists in the United States are more likely than white motorists to have their cars searched by police checking for illegal drugs and other contraband. The courts are faced with the task of deciding on the basis of traffic-stop data whether police are basing their decisions to stop cars on the race of the driver. We develop a model of law enforcement for a population with two racial types who also differ along other dimensions relevant to criminal behavior. We discuss why a simple test commonly applied by the courts is inadequate when the econometrician observes only a subset of the characteristics observed by the policemen. Next, we show how to construct a test for whether di¤erential treatment is motivated purely out of e¢ciency grounds, i.e. to maximize the number of arrests, or re‡ects racial prejudice. The test is valid even when the set of characteristics observed by the policemen are only partially observable by the econometrician. We apply the tests for discrimination to traffic stop data from Maryland. Finally, we present a