If you can get past the teacherly, narcissistic tone, read the ongoing debate between Malcolm Gladwell and the authors of Freakonomics about why the crime rate dropped in the 1990’s in major cities (or in New York–that’s part of the debate actually).
To get you started: Gladwell buys James Q. Wilson and George Kelling’s “broken windows” theory (popularized in the Giuliani administration and, to an extent, by some of Gladwell’s early writing at the New Yorker); the Freakonomics guys think Roe v. Wade had a lot to do with it. (Fewer unwanted children = fewer criminals? Something like that.)
– Tom McGeveran