Diversity won’t solve police misconduct: Black cops don’t reduce violence against black citizens.

According to a ProPublica analysis of federal data on police shootings, young black males ages 15 to 19 are 21 times more likely to be shot and killed by police than their white counterparts. “One way of appreciating that stark disparity,” notes ProPublica, “is to calculate how many more whites over those three years would have had to have been killed for them to have been at equal risk. The number is jarring—185, more than one per week.” What’s most relevant for the diversity of police departments is this fact: While black officers are involved in just 10 percent of police shootings, 78 percent of those they kill are black.

The glib response to stats on blacks and police is to cite so-called “black crime” or “black criminality.” But this depends on a major analytical error. Yes, blacks are overrepresented in arrest and conviction rates. At the same time, “criminal blacks” are a tiny, unrepresentative fraction of all black Americans. If you walked into a group of 1,000 randomly selected blacks, the vast majority—upward of 998—would never have had anything to do with violent crime. To generalize from the two is to confuse the specific (how blacks are represented among criminals) with the general (how criminals are represented among blacks). Statisticians call this a “base rate error,” and you should try to avoid it.

Diversity won’t solve police misconduct: Black cops don’t reduce violence against black citizens.