What Caused the Crime Decline?
Brennan Center for Justice | Dr. Oliver Roeder, Lauren-Brooke Eisen, and Julia Bowling
For the past 40 years, the United States has been engaged in a vast, costly social experiment. It has incarcerated a higher percentage of its people, and for a longer period, than any other democracy. In fact, with 5 percent of the world’s population, the U.S. is home to 25 percent of its prisoners. There are five times as many people incarcerated today than there were in 1970. And prisoners are disproportionately people of color. At current rates, one in three black males can expect to spend time behind bars. This archipelago of prisons and jails costs more than $80 billion annually — about equivalent to the budget of the federal Department of Education. This is the phenomenon of mass incarceration.
Mass incarceration was a distinct response by lawmakers and the public to the social tumult of the 1960s and the increasing crime rate of the 1970s and 1980s. The standard theory supporting incarceration as the primary crime-control tactic posits that incarceration not only incapacitates past offenders, but also deters future ones. Crime across the United States has steadily declined over the last two decades. Today, the crime rate is about half of what it was at its height in 1991. Violent crime has fallen by 51 percent since 1991, and property crime by 43 percent. What was once seen as a plague, especially in urban areas, is now at least manageable in most places. Rarely has there been such a rapid change in mass behavior.
This observation begs two central questions: Why has crime fallen? And to what degree is incarceration, or other criminal justice policy, responsible?
Social scientists and policy experts have searched for answers. Various explanations have been offered: expanded police forces, an aging population, employment rates, and even legalized abortion. Most likely, there is no one cause for such widespread, dramatic change. Many factors are responsible.
This report isolates two criminal justice policies — incarceration and one policing approach — and provides new findings on their effects on crime reduction using a regression analysis. To fully isolate the effects of these two policies on crime reduction, this report also examines 12 additional commonly cited theories about what caused the crime decline. Effects are also separated out by decade: 1990- 1999 (“the 1990s”) and 2000-2013 (“the 2000s”). This distinction helps expose the nuanced effects of variables given the different demographic, economic, and policy trends in each decade.