Did Legalized Abortion Lower Crime?
比较了堕胎合法化前后出生人群的凶杀和逮捕率变化，发现没有一致证据表明堕胎合法化影响了近年犯罪率，认为此前研究发现的显著关联可能源于未测量的时期效应如可卡因使用变化。
Abstract In this paper I compare changes in homicide and arrest rates among cohorts born before and after the legalization of abortion to changes in crime in the same years among similar cohorts who were unexposed to legalized abortion. I find little consistent evidence that the legalization of abortion in selected states around 1970, and then in the remaining states following Roe v. Wade, had an effect on recent crime rates. I conclude that the dramatic association as reported in a recent study is most likely the result of unmeasured period effects such as changes in crack cocaine use.