In Freakonomics Steven D. Levitt argued that crime rates in a locality are linked to abortion laws in the same locality a generation earlier. Basically, in the

In Freakonomics Steven D. Levitt argued that crime rates in a locality are linked to abortion laws in the same locality a generation earlier. Basically, in the US, states that legalized abortions after Roe v Wade 1973 noticed a drop-off in crime starting around 1990, whereas states that did not legalize abortion did not see a drop. He claimed that changes in police methods around the same time were not so statistically significant in altering the crime rate.