Two recent articles, one pro and one con, examine the alleged relationship between legalized abortion and crime. See my post of Nov. 18, 2007.
Christopher L. Foote and Christopher F. Goetz in The Impact of Legalized Abortion on Crime refute the analysis done by John J. Donohue III and Steven D. Levitt in their 2001 paper.
Donohue and Levitt respond in Measurement Error, Legalized Abortion and the Decline in Crime: a Response to Foote and Goetz and confirm their original findings.
The debate goes on.