So the Freakonomics guys famously (and controversially) attributed the decline in crime in the 90's to four factors, abortion being the most controversial [1]: – Increased reliance on prisons – Increased number of police – The bursting of the crack bubble – The legalization of abortion The NYT article says that incarceration rates have dropped, which would eliminate the first factor. I wonder how the other 3 correlat…
http://www.isteve.com/abortion.htm
That this claim is still so often credulously repeated tells you something about how tied to reality the chattering classes are.
The above referenced Steve Sailer also offers a decent unempirical hypothesis about the decline of crime: Technology has made it way harder to do much bad stuff without getting caught. Cell phones and surveillance cameras and better police tech make crime much riskier than it was.
I also suspect everybody's fatter, older, and more couch-potato than they used to be. Obese slobs with 200 channels are too lazy to go gang-banging.