It’s a fact: crime rates in America, on average, dropped by one-third during the 1990s. Today, violent crime has dropped by nearly half since the early ‘90s. Half! So what are some explanations for the lower crime rate we’re enjoying? Are there any crazy crime rate theories out there? Of course there are!
Some of the reasons why crime rates dropped sound fairly sensible, like an increase in the number of police and mass incarceration. Some sound a little nuts, like the one about lead in paint and gas poisoning everyone and making them criminals. But the real reasons why crime has gone down are actually really hard to pin down, and most of the prevailing theories may be overestimating things a bit. As Carnegie Mellon University criminologist Alfred Blumstein told the Chicago Tribune, "no one has a definite explanation." Here are some of the craziest and most controversial guesses.
Theory: The Freakonomics dudes made this one pretty well-known: legalizing abortion with Roe v. Wade, the theory goes, led to about half of the crime decline in the ‘90s. Why? They say fewer kids born in unwanted circumstances meant fewer kids predisposed to violent crime down the road (a so-called “20-year lag effect.”) In 1994, for example, a totally-wanted and non-violent 21-year-old, as Vox points out, would have been born in 1973, the year of Roe v. Wade. That 21-year-old’s totally-unwanted and thus hypothetically-violent hypothetical friend, the hypothesis goes, could have been legally aborted, thus preventing the future violence and crime.
Verdict: Legalized abortion may have reduced crime “to some extent in the 1990s,” but it doesn’t explain the continued decline “after the Roe v. Wade generation was out of prime criminal age.” Another problem with the theory is that “births to unwed teens didn't fall after the abortion decision - they rose.” Some criminologists even say the theory has been “generally … discredited.” Also, Roe v. Wade didn’t exactly invent abortion: “700,000 and 800,000 women terminated their pregnancies each year in the decades preceding Roe.”
Theory: Kids exposed to lead via paint and gas have been linked to complications down the road including “lower IQ, hyperactivity, behavioral problems, and learning disabilities.” Simply put: lead-poisoned toddlers from the ‘40s and ‘50s were more prone to be criminals in the ‘60s, ‘70s, and ‘80s. So what stopped all that in the ‘90s? An economist in 2007 largely attributed the whopping “56 percent drop in violent crime in the 1990s” to the Clean Air Act of 1970, which removed lead from gasoline. It’s a pretty tidy finding, too, as Kevin Drum from Mother Jones points out: “… states where consumption of leaded gasoline declined slowly, crime would decline slowly too. Conversely, in states where it declined quickly, crime would decline quickly.”
Verdict: Critics say removing lead had “at least some effect” on the overall drop in crime, but it doesn’t explain everything because “even people who had been exposed to lead as children started committing fewer crimes” (there’s also some controversy over the source of the data in the 2007 study). Even international and hyper-local studies about lead and crime, however, show remarkably similar findings, and plenty of serious people are pretty die-hard about this. Drum, for example, thinks “solving our lead problem [would] do more than any prison to reduce our crime problem.”
Theory: The widespread use of cell phones may have led to a one-third drop in crime rates in the ‘90s. Studies show that mobile phones “allow for quicker reporting of crimes” and the “perceived risk of apprehension” likely deterred a whole generation of muggers and bad dudes. There’s also the sub-theory that cell phones made “some illegal activities [like drug deals] safer, avoiding encounters that could have easily turned violent in the past.”
Verdict: The main study’s authors note it “wasn’t until the mid-1990s that more than a trivial share of the US population used the technology” but that nicely “coincides with the beginning of the crime decline.” They admit that “it is not possible to state with confidence that there is a strongly negative effect of mobile phone penetration on violent crime rates” but conclude that “cell phone adoption lowers crime” in general. The theory that cell phones lead to safer illegal activities still needs research.
Theory: According to one major study, an increased use in so-called “happy pills” such as Prozac, Ritalin, and Adderall led to a decline “in crimes committed both by and against young people.”
Verdict: Richard Rosenfeld of the University of Missouri St. Louis is a vocal critic of this theory, cited by Vox and The Marshall Project. Rosenfeld says antidepressants and anti-ADHD medications may have helped individual kids on a case-by-case basis, but there’s no “significant research” to support the idea that it helped the population as a whole. He attributes the findings to "simple correlation."