Good Policing Saves Black Lives

A report by Harvard’s Roland Fryer shows that when the cops pull back, homicides increase.

How do you root out bad cops without changing the behavior of good cops?

That’s a question explored in a forthcoming academic paper on policing the police by Harvard economist Roland Fryer and co-author Tanaya Devi. Given the current nationwide protests and mob violence ignited by the death of George Floyd in Minneapolis, it’s a subject on the minds of many.

In 2016 Mr. Fryer released a study of racial differences in police use of...