This is a long article, but it’s worth reading the whole thing. I learned some things I didn’t expect to.
Of course I already knew that the relationship between race and crime rates was very strong. The two most surprising things to me were
(1) New York City is a huge outlier which strongly affects the nationwide results. The relationship between race and crime would be much stronger if New York City is excluded. What New York City shows is that changes in policing can tremendously reduce urban crime, and that therefore the racial statistics are much less depressing.
(2) Many right-wingers, baffled by the enthusiasm of American elites in both political parties for unrestricted immigration, see this as a sinister plot to replace white people with a politically and economically more controllable population. The author makes an interesting argument that an even bigger motivator is the desire to displace black people.
I knew about this problem, but I had no idea how much of the crime statistics it explained. One of the most disturbing things about the article is how hard it has been to get people whose job it is to understand the causes of crime to pay attention to this research. Almost everyone has their own pet theory, which accepting this environmental explanation would reduce the relevance of.