(Duplicated from a comment I made to the original posting of this article at https://news.ycombinator.com/item?id=5002806...)

Via http://election.princeton.edu/2012/12/22/scientific-american, which cited Reyes' work on the lead theory, here's a link to a striking critique of the abortion theory:

http://www.economist.com/node/5246700?story_id=5246700

Someone inspected Donohue and Levitt's code and found a bug that meant they hadn't controlled for what they claimed they had. "Fixing that error reduces the effect of abortion on arrests by about half, using the original data, and two-thirds using updated numbers."