>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.
I think this is yer basic correlation/causation confusion, maybe even estimating a negative identity. As our society only recognizes crime (outside the civil sphere at any rate) as a crime if it is identified and reported as such by the police, lower numbers of police will, in almost all cases, lead to less crime being reported.
That's a gross simplification, societal attitudes and mores play a role in these things as well; the rate of reported spousal abuse has increased significantly in the last 20 years, does that mean there's more of it or hat it's just being reported more? Crimes like sexual assault are subject to the same thing; the amount of crime being reported is directly proportional to having recognized 'authority figures' who validate that a crime occurred and a society willing to prosecute an action as a 'crime'. Hence why capitalist society has laughable laws on economic violence like minimum wages and gender/racial discrimination.
I had a great stats prof years ago who phrased it this way; do more firemen at a fire cause a bigger fire? Make sure you have the chain and direction of causation correct before making assumptions about what a correlation means or 'proves'.
PC
N P Childs
'I'm Mister Bad Example, the stranger in the dirt, I like to have a good time and I don't care who gets hurt'.
-Mr. Bad Example, W Zevon