Huh? First, who proved this? And second, how can you tell causation doesn't run from crime to cops? NYC has a very large police force, and the lowest crime rate of any big city in the U.S.
Doug
I was partly joking, but I think the Sentencing Project has some stuff on this, or maybe it's in one of Marc Mauer's books--the effect is a result of, if you don't get stopped and, for example, found to have pot in your car, well, then, no crime occurred, right? Peeing in the bushes is only peeing in the bushes unless a cop is there and then it's indecent exposure (homeless people around here get busted for this and guess what, it goes on your record as a sex offense.) In other words, many crimes only become crimes (in terms of reporting) when cops are there to bust you. Another example: if you get stopped for Driving while Black and then beat up and therefore charged with assaulting a cop, the cop causes the 'crime' (the real crime, of them assaulting you, probably isn't in those stats but it would bump it up more.)
I think they dealt with causation through examination of chronology.
Jenny Brown