5/14/2005

Levitt and Dubner on Crime

From Tom Roeser's piece in today's Chicago Sun-Times

. . . Levitt makes it clear he is no cheerleader for abortion, declaring that he must go where the statistics lead. He's right. But do the statistics lead there? And does he persist in his theory when he's proved wrong?

John Lott, another U. of C.-trained economist and now resident scholar at the American Enterprise Institute, says in a letter in the Wall Street Journal that legalization doesn't explain ''75 percent of the drop in murder rates, and if anything the reverse is true. Their data had a serious error . . . incorrectly claim[ing] that when abortion was legalized during the late 1960s and early 1970s, states went from a complete ban to complete legalization, but abortions had been allowed before complete legalization when the life or health of the mother was endangered. The Centers for Disease Control and Prevention show that before Roe vs. Wade, many states that had allowed abortions only when the life and health of the mother was endangered actually had higher abortion rates than states where it was completely 'legal.' If Messrs. Levitt and Dubner were correct, crime rates should have started falling among younger people who were first born after legalization. Only as they aged would you start seeing crime fall among older criminals. But in fact the precise opposite is true. Murder rates during the 1990s first started falling for the oldest criminals and very last for the youngest.''

Magazine writer and blog-meister Steve Sailer sails in with more data. Murder rates are now rising, says the FBI. From 1999 through 2002 (the latest data available), the murder rate jumped 17 percent among 25- to 34-year-olds born long after Roe. ''[T]he most obvious explanation for the ups and downs of the murder rate is the ups and downs of the crack business,'' he says. ''This generation, born right after legalization, is better behaved today in part because so many of its bad apples are now confined to prisons, wheelchairs and coffins.''

These are interesting challenges to a book that is causing Americans to debate its findings at office water coolers and at cocktail parties. It turns out that Sailer had debated Levitt on these facts before the book was published. Why weren't Sailer's facts taken into consideration when Levitt wrote the book? This he doesn't seem to do -- at least when confronted by Bill O'Reilly on Fox News the other night. It's a good book. Now, if Levitt would respond to Lott's and Sailer's challenge in our letters to the editor, it would be even better!.


Of course, they didn't just ignore Sailer's claims. I provided the corrected abortion data to Levitt and Donohue back in 1999, well before they had even published the first version of their abortion and crime research. Unfortunately, they didn't deal with it in their QJE piece. (My work with John Whitley shows how that this has a big impact on their results..) For the entire Wall Street J. letter see here. Note I have corrected an error that was in the op-ed's second paragraph above.