Do crime reduction efforts — like building more prisons — really pay?
A new national study says that states with the biggest jumps in incarceration levels have not shown corresponding drops in crime, compared to states with smaller increases in their population behind bars.
“It seems like the more we expand the prison system, the fewer benefits we get in terms of crime reduction,” says Marc Mauer, one of the authors of the study released today by the Sentencing Project, a research group that advocates alternatives to incarceration.
The study says that between 1991 and 1998, the 20 states with the highest rise in prison population — a 72 percent increase on average — recorded a 13 percent reduction in crime. It says the 30 states with smaller rises in prison population — averaging a 30 percent increase — had their crime rates drop 17 percent.
While Texas, which led the nation in raising its incarceration rate 144 percent over the study’s years, saw a significant drop in its crime rate of 35 percent, other large states showed similar drops with smaller rises in prison population. California, Massachusetts and New York all saw their crime rates decrease sharply during the years of the study.
The Sentencing Project study also says while prison population increased continuously nationwide between 1984 and 1991, crime rates fluctuated significantly.
The lack of correlation bolstered the claim that there is no strong relationship between imprisonment and crime, Mauer said.
Serious crime dropped 7 percent last year, continuing a trend that began in 1992.
An estimated 28.8 million violent and property crimes were committed last year, compared to 44 million in 1973 when the FBI first released its annual crime survey.
Mauer cites the improved economy, changes in the drug trade, new policing methods and demographic shifts as factors behind the drop.
Based on his own research, Richard Rosenfeld, a criminologist at the University of Missouri at St. Louis, says that perhaps 20 percent of the recent crime drop is due to increased incarceration.
Like Mauer, he attributes the remainder to the booming economy, continued decline in crack cocaine use, and other factors. Rosenfeld says the aging of the baby boom generation is an important factor behind the drop, because older populations generally commit fewer crimes.
The study concludes that given the high financial cost of incarceration, building more prisons is no longer the best way to lower crime rates.
The Sentencing Project’s analysis says the states that had above average rates of incarceration during the years covered by the study spent an extra $9.5 billion dollars to achieve a 2 percent decrease in crime rates.
There are more than 2 million people incarcerated in the United States. With many studies putting the cost of imprisonment at $20,000 per prisoner per year, an estimated $40 billion is spent on incarceration annually in the country.
Rosenfield also raises questions about the cost effectiveness of incarceration.
His study, which will be published next month in an anthology titled The Crime Drop in America, claims that to avert one killing, it required locking up 670 individuals, based on demographic patterns in high-crime areas.
He puts the cost of those additional incarcerations at $13.7 million per year.
“It’s not for a social scientist to say” if that is an acceptable price, he stresses, but he believes policy-makers ought to consider other approaches to crime reduction.
Causation, or Simply Correlation?
Criminologists, including Rosenfeld, are wary of drawing conclusions from the Sentencing Project’s research, however.
“I find the Sentencing Project’s findings suggestive, but we need more facts,” Rosenfeld says. “It’s not terribly definitive.”
Paul Robinson, a criminal law professor at Northwestern University, says the Sentencing Project’s state-by-state comparisons of crime rates and incarceration “tell us nothing, absolutely nothing.”
“Correlation is not cause,” he stresses. “It tells us nothing about cause.”
Robinson believes there are too many variables when comparing different states, and that the complexities defy simple conclusions about the effectiveness of imprisonment. “I don’t think we know enough to decide [whether to build more prisons],” he says.
Daniel Nagin, a criminology professor at Carnegie Mellon University agrees with Robinson, in part. “These kinds of estimates are of limited value,” he says.
Mauer acknowledges that a variety of factors may be behind the stunning drop in crime in recent years, but he says his study serves an important function nonetheless, by challenging the idea that more prisons necessarily mean less crime.
The Sentencing Project study shows “the one thing you certainly can’t do is to assume that building new prisons will give you a substantial reduction in crime,” he says.