Bloomberg-Business Week cites research by Professor John Donohue in an analysis of preventative measures against racial profiling by police officers. 

The clash between police and citizens in Ferguson, Mo., highlights an American dilemma about law enforcement. After the Missouri State Highway Patrol took over policing on Thursday night, the streets of Ferguson became considerably more peaceful than they had been under the watch of St. Louis County police.

As the crisis has starkly illustrated, we’ve been increasing the power of every police force in terms of weapons, authority, impact, and indemnity. But the quality of policing hasn’t always kept up with the elevated power—nor has our ability to test and improve that quality. The U.S. should look to other countries for techniques of measuring police probity and foster reforms to strengthen the caliber of the nation’s law enforcement system.

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In New York, for example, the stop-and-frisk program expanded, leading to almost 700,000 cases in 2011 in which police with “reasonable suspicion” stopped, interrogated, and patted down people across the city. Four out of 10 of those stops involved black and Latino males aged 14 to 24–a group that makes up less than one-twentieth of the city’s population. (The program is currently the subject of an appeals court case over its constitutionality, and the number of stop-and-frisks has dramatically declined over the past year.) Analysis by John Donohue of Stanford University and Steven Levitt of the University of Chicago found that the more white police are hired by police departments, the higher the arrest rate for nonwhites climbs, while the rate of arrests for whites stays constant. (Similarly, Donohue and Levitt found, hiring more nonwhites leads to an increase in the white arrest rate.) In Boston, officers are more likely to search a car if the race of the officer and driver are different.