This article struck me because it’s so contrary to the general wisdom (including mine). The US has a far lower percentage of police than other developed nations. The article claims this is related to our insanely high imprisonment rate:
we have a low certainty of punishment (measured as arrests per homicide) and then try to make up for that with high punishment levels (prisoners per arrest). The low certainty, high punishment level is especially notably for black Americans.
One problem I see here is that it doesn’t consider differences in quality of policing, especially the militarization of policing that’s been happening in the US over the past couple of decades.