Monday, April 23, 2007

Racial Profiling Doesn't Work

A strong reason for law enforcement officers to target minorities, particularly Black and Hispanic motorists, is the common belief that they are more likely to be violating laws, particularly drug laws than non-minorities. Minority communities have long perceived that they are being targeted and evidence has accumulated that at least some of that perception is reality. But what of the perception, by many in society and in police departments alike, that minorities are more likely to be violating drug laws?

Since 1995 direct evidence has accumulated concerning the assertion that minorities are more likely to have contraband when they are stopped and searched by the police. The first report of these data came from Dr. John Lamberth in the case brought by Robert Wilkens against the Maryland State Police. Lamberth reported that Blacks and Whites were equally likely to have contraband found when they or their cars were searched. Since that time, at least nine other studies have been released that show the same phenomenon. The results of all of these studies are shown in Figure 1 below:

These studies are impressive in the breadth of situations and location they encompass. The largest one, of course, is a survey by the Department of Justice, Bureau of Justice Statistics in which 1,272,282 searches are detailed. This survey covers all encounters of citizens with police during 1999. There are, however, other types of search activities, e.g. Customs in Airports, and locations, e.g. a report from the London Metropolitan Police. The most impressive finding of these studies is their consistency. In every one, minorities are no more likely to be carrying contraband than non-minorities, and in several of the studies they are statistically significantly less likely to have contraband found following a search.

This overwhelming evidence against the proposition that minorities are more likely to commit crimes that can be discerned during vehicle searches points out how counterproductive racial profiling is. That is, by concentrating on minorities, law enforcement ineffectively use valuable time and resources by engaging in search activities that are likely to be unproductive. There is, however, even more direct evidence that racial profiling is wasteful of police resources.

In 1998 the Customs Service of the U. S. Government decided that their low hit rate and complaints from minorities that they were being targeted warranted a re-evaluation of their search procedures. The Service adopted reforms designed to eliminate racial, ethnic and gender bias in their search activity, while instituting stronger supervisor oversight for searches. While the Service has not released their search criteria, we can look at the results of their experience and view the results, which are contained in Figure 2 below.

The Figure, which is a comparison of searches and hit rates of minorities for 1998 and 2000, makes clear several important concepts. The most important point about the 1998 data are that the “hit rates” for Blacks and Whites are virtually identical, while the hit rate for Hispanics is considerably lower than for the other two groups. Another important piece of information from a management and resource utilization point of view is that contraband was found in less than 4 out of a 100 searches.

The 2000 data are intriguing. Searches dropped by a startling 75%. The total number of hits, however, was essentially the same as in 1998. The hit rate for Blacks, Whites and Hispanics went up almost 300%. This, of course, is another way of saying that the Customs Service cut its workload of searches by three quarters without reducing the number of successful searches for contraband carrying passengers. This, of course, occurred while reducing by three quarters the number of innocent people who the Service subjected to the indignity of a search. For our purposes the most important statistics from Figure 2 are the hit rates which are essentially the same for Whites, Blacks and Hispanics. So while the Customs Service changed its tactics and increased its hit rate, there was no difference in the percentages of people found to be carrying contraband by race.


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