"The timing of the break in the national crime rate is consistent with a legalized abortion story. In 1991 the first cohort affected by Roe v. Wade would have been roughly seventeen years old, just beginning to enter the highest crime adolescent years. In the early-legalizing states (in which slightly more than 20 percent of all Americans reside), the first cohort affected by legalized abortion would have been twenty years of age, roughly the peak of the age-crime profile [Blumstein et al. 1986; Cook and Laub 1998]."