What's Behind The Decline In Crime?

Last Updated: Jun. 12, 2015

May 28, 2015 | By Neil Howe

This editorial originally appeared in Forbes.

From Bed-Stuy to South Central Los Angeles, areas once known for drug lords and drive-bys are gentrifying. Today, murder rates in these areas are barely a third of what they were in the early 1990s—the starkest reflections of a nationwide decline in crime. While the public remains largely unaware of this drop, experts have been observing and discussing it for years. Though many theories have been considered, one explanation that is often missing from the debate is generational change: Crime rates started to fall precisely when Millennials entered the prime age bracket for criminal activity.

Crime rates have plunged since the mid-‘90s. After rising sporadically from the early ‘60s onwards, crime rates reached unprecedented peaks in the ‘80s and early ‘90s. It wasn’t until 1995 that crime’s climb gave way to decades of decline. As of 2013, the rate of violent crime victimization, as measured by the U.S. National Victimization Survey, is down 71% from its peak in 1994. Over this same period, the rate of violent crime victimizations for 12- to 24-year-olds—the age bracket most likely to commit crime—fell 78%. Many of these youths are moving to large cities, which is just where violence has subsided the most. Washington, D.C. and Los Angeles have experienced 76% and 90% decreases in the murder rate since 1992, respectively.

Interestingly, the public remains largely unaware of this trend. In every annual Gallup poll since 2003, a majority of American adults have said that crime is rising. And in a 2013 poll, 56% of Americans said that the number of gun crimes is higher than it was two decades ago—even though gun violence peaked in 1993. The public also clings to outdated notions about which cities are the most dangerous. Although New York City’s violent crime rate is about half that of Dallas or Houston, survey respondents continue to rank New York as the second-most unsafe city in the country and Dallas and Houston as the safest.

Experts are well-aware of this trend and have generated a multitude of theories, none of which hold up under scrutiny. The prosperity thesis argues that crime rates fall when economic conditions improve and rise when the economy sours. While this reasoning seemed to explain falling crime rates during the economic boom of the late ‘90s, it doesn’t explain why crime continued to fall during the recent recession.

Another set of explanations credits changes to the criminal justice system. According to the incarceration argument, crime has declined because more potential offenders are behind bars. But crime rates have continued to fall in states that have lowered their incarceration rates. And the incarceration rate of young offenders is going down (as the rate of older offenders goes up). Another argument is that the death penalty deters criminals. But capital punishment has been in decline since the early ‘00s—and crime rates have continued to fall. Others credit a larger police presence and improved policing tactics. Yet if this were the main driver, we would expect to see dramatic city-by-city differences based on which cities implemented these new tactics—but we don’t see much variation.

More persuasive are explanations that point to environmental and social factors. Backed by scientific evidence, several of these theories are widely credited for playing at least a minor role in crime’s decline. Perhaps the most popular—the lead hypothesis—argues that exposure to lead causes aggressive behavior. Evidence links the passage of the 1970 Clean Air Act and the phasing out of lead from gasoline and paint to decreased crime levels.

Others point to the decreased consumption of substances (such as crack cocaine and alcohol) linked to violent behavior and criminal activity. Freakonomics even links the passage of Roe v. Wadein 1973 with crime’s decline, contending that the shrinking number of unwanted babies showed up as a crime decline 18 or 20 years later. (According to this logic, however, crime rates should have risen when abortion rates began falling in the 1980s. This did not happen.)

So what other major explanation is there? Maybe the best candidate is generational change. Youth crime rates started to rise in the late ‘60s, just as the first wave of Boomers entered the youth age bracket. For the next couple of decades, Boomers and first-wave Xers took youth violence to spectacular heights.

It wasn’t until the late ‘90s and early ‘00s—just as Millennials entered the scene— that crime rates began their sharp descent. Unlike Boomers and Xers, Millennials were increasingly looked after, sheltered, and advised to not take risks. As they moved up the age ladder, this generation brought about declines in risky behaviors—including rates of school fighting, teenage pregnancy, smoking, drunk driving, and so on. (See the extensive CDC database on the decline in so-called “youth risk behaviors.”) Of these trends, crime was just one element.

Many of the possible explanations put forth by experts can be regarded as further manifestations of Millennial trends. The removal of lead, for instance, is just one of many precautions public officials took to protect young Millennials from harm. And while Boomer and Xer youth dabbled in recreational drug use (habits they continued as they aged), Millennials have brought about declines in youth drug abuse and alcohol consumption (except for marijuana).

Not only does generational change explain why the decline in crime spans from coast to coast, but it also helps explain why the public continues to believe that crime is rising. In today’s world, when a child goes missing or a teenager is murdered, it makes headlines across every media platform—which, in part, reflects a world that is less tolerant of violence.  This means that neighborhoods plagued by crime in the ‘90s will have a difficult time shaking their bad reputations. And as Millennials increasingly move into these urban areas—transforming former hotbeds of crime into havens for hipsters—they will continue to receive frantic phone calls from their concerned parents for many years to come.