What Caused the Crime Decline?

February 12, 2015

What Caused the Crime Decline? examines one of the nation’s least understood recent phenomena – the dramatic decline in crime nationwide over the past two decades – and analyzes various theories for why it occurred, by reviewing more than 40 years of data from all 50 states and the 50 largest cities. It concludes that over-harsh criminal justice policies, particularly increased incarceration, which rose even more dramatically over the same period, were not the main drivers of the crime decline. In fact, the report finds that increased incarceration has been declining in its effectiveness as a crime control tactic for more than 30 years. Its effect on crime rates since 1990 has been limited, and has been non-existent since 2000.

More important were various social, economic, and environmental factors, such as growth in income and an aging population. The introduction of CompStat, a data-driven policing technique, also played a significant role in reducing crime in cities that introduced it.

The report concludes that considering the immense social, fiscal, and economic costs of mass incarceration, programs that improve economic opportunities, modernize policing practices, and expand treatment and rehabilitation programs, all could be a better public safety investment.

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By Dr. Joseph E. Stiglitz, University Professor at Columbia University, former Chairman of the United States Council of Economic Advisers, and a 2001 recipient of the Nobel Memorial Prize in Economic Sciences.

Our country has its share of challenges — poverty, unemployment, inequality. Economic analysis can help play a role in understanding and addressing these challenges.

One of the great problems we face today is mass incarceration, a tragedy which has been powerfully documented. With almost 1 in 100 American adults locked away behind bars, our incarceration rate is the world’s highest — nine to ten times that of many European countries. This adds up to an overwhelming 2.3 million people in prison and jail today — nearly 40 percent of whom are African American.1 Yet lawmakers are slow to take action and public outrage is largely absent.

This prodigious rate of incarceration is not only inhumane, it is economic folly. How many people sit needlessly in prison when, in a more rational system, they could be contributing to our economy? And, once out of prison, how many people face a lifetime of depressed economic prospects? When 1 in 28 children has a parent in prison, the cycle of poverty and unequal opportunity continues a tragic waste of human potential for generations.

Americans spend $260 billion every year on criminal justice. That is more than one-quarter of the national deficit.2 A year in prison can cost more than a year at Harvard. This is not a hallmark of a well- performing economy and society.

This vast fiscal and social toll was created in the name of protecting lives and property. But what do we know about the public safety benefits, the ostensible justification for our prison-centered approach to crime?

Some advocates of this system of mass incarceration seem to contend that while the costs have been enormous, so have the benefits, the dramatic drop in crime. They would like to believe that this can be attributed in large measure to the explosion in incarceration. After all, when offenders go to prison, it would seem they are less likely to commit future crimes. But this instinctive reaction does not comport with the scientific evidence.

This report addresses a critical question: What caused the American crime decline? Was it incarceration? Was it policing? Or was it something else? This groundbreaking empirical analysis from the Brennan Center shows that, on examination, the easy answers do not explain incarceration’s effect on crime. This report presents a rigorous and sophisticated empirical analysis performed on the most recent, comprehensive dataset to date.

The authors conclude that incarceration had relatively little to do with the crime decline. They find that the dramatic increases in incarceration have had a limited, diminishing effect on crime. And they have quantified those minimal benefits. At today’s high incarceration rates, continuing to incarcerate more people has almost no effect on reducing crime.

These findings raise questions as to whether the toll — fiscal, economic, and societal — of mass incarceration is worthwhile in the face of these negligible crime control benefits. The report also demonstrates the value of interdisciplinary thinking. It melds law, economics, science, criminology, and public policy analysis to address the challenges facing our country.

The United States has limited resources. We must foster opportunity and work to bridge inequality, not fund policies that destroy human potential today and handicap the next generation. The toll of mass incarceration on our social and economic future is unsustainable.

When high levels of incarceration provide scant public safety benefit, it is pointless to continue using — wasting — resources in this way. Instead, the country should shift priorities away from policies proven to be ineffective and focus our energies on truly beneficial initiatives that both reduce crime and reduce mass incarceration. The evidence presented here tells us that these are compatible goals.