Excellent analysis.

The reason Levitt cites European studies claiming that women who have abortions would make worse mothers than the ones who have their children in his study of _American_ crime trends is because the American studies of the impact of abortion came to the opposite conclusion.

Trent and Griner's research, along with other studies undermining Levitt's central argument, was pointed out to Levitt by CCNY economist Ted Joyce in his response to Levitt & Donohue in the Journal of Human Resources, which was entitled "Did Legalized Abortion Lower Crime?" Joyce summed up two reason why Levitt's theory didn't work. The second was:

"Second, analysts, I being one, have tended to overestimate the selection effects associated with abortion. A careful examination of studies of pregnancy resolution reveals that women who abort are at lower risk of having children with criminal propensities than women of similar age, race and marital status who instead carried to term. For instance, in an early study of teens in Ventura County, California between 1972 and 1974, researchers demonstrated that pregnant teens with better grades, more completed schooling, and not on public assistance were much more likely to abort than their poorer, less academically oriented counterparts (Leibowitz, Eisen, and Chow 1986).

"Studies based on data from the National Health and Social Life Survey (NHSLS) and the National Longitudinal Survey of Youth (NLSY) make the same point (Michael 2000; Hotz, McElroy, and Sanders 1999). Indeed, Hotz, McElroy, and Sanders (1999) found that teens who abort are similar along observed characteristics to teens that were never pregnant, both of whom differ significantly from pregnant teens that spontaneously abort or carry to term.

"Nor is favorable selection limited to teens. Unmarried women that abort have more completed schooling and higher AFQT [the military's IQ test for applicants for enlistment] scores than their counterparts that carry the pregnancy to term (Powell-Griner and Trent 1987; Currie, Nixon, and Cole 1995).

"In sum, legalized abortion has improved the lives of many women by allowing them to avoid an unwanted birth. I found little evidence to suggest, however, that the legalization of abortion had an appreciable effect on the criminality of subsequent cohorts."