February 3, 2014 | Chemical & Engineering News
When crime rates began to drop across the U.S. during the 1990s, city officials and criminologists were thrilled—but baffled. Violent acts, most often committed by young adults, had reached an all-time high at the start of the decade, and there was no sign of a turnaround.
By the close of the ’90s, though, the homicide rate had declined more than 40% throughout the country. Economists and criminologists have since proposed reasons for the unexpected plummet. Some have pointed to an increase in police officers. Others have suggested a rise in the number of offenders put behind bars. Economist and “Freakonomics” coauthor Steven D. Levitt famously hypothesized that the legalization of abortion in 1973 even played a role. Once the Supreme Court decided Roe v. Wade, he argued, fewer unwanted babies grew into disturbed, crime-prone adults two decades later. [...]