I found this article posted on The Well, which I am reproducing here in case anybody wants to investigate further:

Interesting guest on John Stewart last night, an economist who has released
a book called Freakonomics, which applies economic theory and formulas to
everyday life issues. One thing the studied was the societal effects of
abortion, and their model credited Roe V Wade for enabling the lower crime
rates of the 90s much more than the increased police forces. The basic
theory being that unwanted children are more likely to grow up to be
antisocial. John actually did a pretty good job of grilling the guy on what
else might be involved, but the guy was unflappable on his analysis, saying
they had considered all of those other factors and still considered
legalized abortion to be key based on their statistical analysis of crime
rates in states with high abortion rates versus states with low abortion
rates.