Do We Incarcerate Too Many People?

Richard Berk

From the 1970s until about 2010, the number of individuals incarcerated in state prisons, federal prisons, and local jails increased dramatically. The main drivers were (1) changes in laws leading to longer, often mandatory, sentences, (2) "truth-in-sentencing" legislation requiring individuals convicted of violent crimes to serve at least 80% of their sentences, and (3) increased use of incarceration for drug-related crimes. Since then, there have been concerted efforts in some jurisdictions to reduce the number of individuals incarcerated. As a result, the number of people behind bars has declined. Still, as of 2012, about 1 in 100 adults in the United States were in prison or jail, which is at least five times greater than in Western Europe and other democracies.


As a form of punishment, incarceration can be justified in part by moral prescriptions that individuals convicted of crimes owe society reparations for the harm they have caused. When the severity of punishment is thought to be appropriate for the severity of the crime, offenders can be seen as getting their "just desserts." As a practical matter, however, there is no easy way to translate crime seriousness into prison sentences of different lengths. For example, murder probably demands a longer sentence than armed robbery, but exactly how much longer?


In practice, incarceration can be justified by three actionable goals: incapacitation, specific deterrence, and general deterrence. Incarceration incapacitates by preventing inmates from committing new crimes outside of prison. Incarceration can serve as a specific deterrent insofar as individuals who have served time behind bars are less inclined to commit new crimes after release. Incarceration can serve as a general deterrent insofar as individuals who have not been incarcerated are less inclined to commit crimes because they fear incarceration. All three goals can be in service of public safety.


But the public safety necessarily comes at a price. Some costs are in tax dollars. For example, a year in prison can cost as much as a year of college tuition. There are also costs to offenders, who while in prison lose income they may have earned, and who are released from prison with the stigma of being a convicted criminal. Their family members suffer from lost income, absent parenting and foregone companionship. Communities bear costs as well, especially when large numbers of young men are removed.

Consequently, from a public safety perspective, one should balance the costs of incarceration against its benefits. What do we know about that?

Many incarcerated individuals pose little or no threat to public safety. For these offenders, there can be far more cost-effective ways to intervene than with incarceration. Substance abuse treatment programs are one example. A large number of individuals are jailed, not because they have been convicted of a crime, but because they cannot make bail. More generally, deterrence depends far more on the certainty of punishment and the speed with which sanctions are applied, than on the severity of the punishment. If punishment is swift and sure, there can be for most offenders little public safety justification for long prison terms. One policy implication is that more crime fighting dollars need to be invested at the front end to increase police clearance rates and to resolve criminal charges quickly.


Evidence for these claims comes from three kinds of studies. First, although the mass incarceration of the past several decades helped to reduce crime, the effect was probably small. Second, for some inmates, incarceration may increase their threat to public safety. Even if prisons are not automatically "schools for crime," incarceration can sever constructive ties offenders have with their families and communities, and make it very difficult to find employment. Finally, there have been recently in several jurisdictions decisions to increase substantially the number of inmates released before the end of their prison sentences. There is no evidence that these inmates were more likely to commit new crimes than those who had served their full terms.


These studies do not provide justification of the wholesale release of prisoners. They provide justification for the selective release of inmates who demonstrably pose few risks to public safety. For example, criminals typically "age out" of crime; inmates well past their high crime years can be released with few concerns about new, serious crimes that might be committed. There are modern risk assessment tools that can identify large numbers of inmates who for a variety of reasons poise little or no threat. There are also inmates who, because of poorly thought out legislation, were given long, mandatory, sentences far out of proportion to the seriousness of the crimes for which they were convicted. Such sentences serve no useful crime-fighting purpose. Finally, there are inmates who make constructive changes in their lives while incarcerated and become less dangerous as a result.


There will be a substantial number of inmates who continue to pose a serious threat to public safety. Those inmates should not be released before the end of the official prison terms. In short, what makes sense is large scale, smart de-incarceration not large scale, thoughtless, de-incarceration.


The facts just summarized appear to have been overlooked in recent calls at the federal level to crack down on drug offenders. Among the claims made is that such individuals are responsible for a very large proportion of violent crimes, especially homicides. It is, therefore, the job of federal prosecutors to seek the maximum penalties the law allows, especially longer prison terms for those involved in drug trafficking. For drug crimes, there is a call for more incarceration, not less. 


Yet, the vast majority of drug arrests are processed at the local level where federal practices are largely irrelevant. For example, city district attorneys, not federal prosecutors, do the charging. After a felony conviction, offenders are sentenced to state prisons, not federal prisons. In addition, the vast majority of violent crimes are not related to drug use, even drug trafficking. Homicides, for instance, are far more likely the result of interpersonal disputes or robberies “gone bad,” neither of which are drug-related. 


The call for federal prosecutors to get tough on drug crimes is not based on the available evidence. An informed policy would call for sentences that are sure and swift, not more punitive, and that would be applied to the small fraction drug offenders whose illegal actions pose a substantial threat to public safety. There would also be a clear acknowledgement that most drug offenders are not charged, tried and sentenced within the federal criminal justice system. If there is a problem, it is for the states to handle. 



Rossi, P.H., and Berk, R.A. (1997) Just Punishments: Federal Guidelines and Public View Compared. New York: Aldine De Gruyter.


Sessions, J. (2017) ``Being Soft on Sentencing Means More Violent Crime. It’s Time to Get Tough Again.’’ Washington Post, June 16, 2017.


Travis, J., Western B., and Redburn, S. (2014) The Growth of Incarceration in the United States: Exploring Causes and Consequences. Washington, D.C., The National Academies Press.