In the spring of 1968, with crime rising at alarming rates across the country, Republican candidate for president Richard Nixon gave a speech in New York City outlining his solutions for America’s lawlessness. “A society that is lenient and permissive for criminals,” he said, “is a society that is neither safe nor secure for innocent men and women.”
Nixon’s sentiments were early signs of a new “tough on crime” mentality that took hold in the United States during the 1970s. In the decades since, many policymakers have pushed harsher penalties and mandatory minimum sentences in the belief that swift and certain punishment is key to public safety. This mentality has contributed to America’s sky-high rates of incarceration: The US has more people per capita behind bars than any nation in the world — almost 2 million people at present.
And while imprisonment may well provide punishment and sequester criminals away from public life for a time, that may be all it does: A large body of research finds that spending time in prison or jail doesn’t lower the risk that someone will offend again. In some instances, it actually raises the likelihood that they will commit future crimes.
“We do spend a lot of money and we engage in a lot of deprivation of liberty, and the return on that is pretty low,” says Charles Loeffler, a criminologist at the University of Pennsylvania. The question now is, how can we make our criminal justice system more productive?
One important step, says Loeffler, is to be smarter about whom we incarcerate, saving jail and prison for people who are a true public safety risk but avoiding imprisonment in situations where it’s likely to worsen crime.
Equally important is changing how we incarcerate people, by implementing programs aimed at reform rather than punishment, he says. Whether they’re education courses, meaningful work opportunities or specific types of therapy, evidence suggests that rehabilitative programs can significantly reduce criminals’ risk of committing future crimes.
Many people say we do such a poor job with incarceration that we should just do less of it, says Loeffler, who provides an overview of the research in the 2022 Annual Review of Criminology. “An even better policy would be, can we use less of it, but when we do use it, can we do it differently?”
The logical criminal
The theory that time behind bars will deter crime has its roots in the 18th century, when Italian jurist Cesare Beccaria and English criminologist Jeremy Bentham developed the idea of the rational criminal. They argued that all criminals are logical — that they analyze the costs and benefits of committing a crime and proceed only if there’s a net gain. If punishments are swift, certain and proportional to the offense, they theorized, would-be criminals will conclude that crime doesn’t pay.
Beccaria’s and Bentham’s ideas fell out of favor by the second half of the 19th century, but were revived in the late 1960s by American economist Gary Becker. Becker’s work came as the United States was experiencing a massive crime wave, with violent crime in particular rising 126 percent in just one decade. The theory of the rational criminal suggested a solution, and helped to spur the “tough on crime” policies of the 1970s and 1980s that spawned a dramatic increase in the number of people serving time in US jails and prisons.
Yet there were already some hints that jail and prison might not deter crime. In the 1930s, observations by sociologist Clifford R. Shaw suggested that bringing criminals together could promote bad behavior among troubled people, leading to more crime rather than less. He wrote of prison as a “house of corruption” in which criminals might learn new techniques from each other. The work of other scholars in the 1950s and 1960s heightened this concern.
Today, a large body of research backs those early observations, concluding that jail time doesn’t discourage criminals from future crime.
In 2015, for example, an analysis by Swiss researchers looked at 14 studies that compared what happened when criminals were put behind bars to what happened when they were given some other sentence, such as probation or electronic monitoring, that allowed them to stay out of jail or prison. The researchers found that crime rates were just as high for people who’d spent time behind bars as for those who hadn’t.
In 2021, a much larger analysis of 116 studies reached a similar conclusion: Spending time behind bars either didn’t affect a person’s future crime risk or slightly increased it, compared with people who received a sentence that didn’t involve imprisonment. That finding held true for men and women, young people and adults, people who served time in county jails and those housed in state prisons. In no situation did time behind bars reduce a criminal’s risk of future crime, Damon Petrich of the University of Cincinnati reported in the journal Crime & Justice.
It’s possible, of course, that the people who are sentenced to serve time are more likely to commit crime in the first place — in other words, maybe they get put behind bars precisely because judges recognize that they are a crime risk. That could explain the small increased likelihood that a person will commit future crimes after spending time behind bars. To tackle this question, Loeffler and his Annual Review coauthor Daniel Nagin, a criminologist at Carnegie Mellon University, collected a set of 13 carefully designed studies looking at court systems that did things differently: They randomly assigned criminal cases to judges within the court (in other court systems, case assignment isn’t random). If the future crime rate ended up lower for people sentenced by lenient judges than by judges who sent more people to jail, it would be clear evidence that time in jail — not any quality within the criminals themselves — was making the difference.
When Loeffler and Nagin combed through the data, though, they found that the recidivism rate — the rate of future crime — was generally similar for the cases decided by lenient judges and those decided by more punitive judges. In other words, spending time in jail didn’t increase crime, but it didn’t decrease it either.
Doubts about pretrial detention
Loeffler and Nagin’s analysis did turn up a specific situation where incarceration was consistently linked to an increased likelihood of committing a crime in the future: pretrial detention. This is when people who have been accused of a crime are held in jail while they are awaiting trial. In the US, more than 400,000 people are awaiting trial in jail at any given time.
The finding was preliminary, Loeffler stresses, and more research is needed to confirm the effect. But the data suggest that people held in jail before trial have a higher likelihood of committing crime after their release than people who remain in the community before trial.
It’s not surprising that pretrial detention would have a crime-promoting effect, says Nazgol Ghandnoosh, a research analyst at the Sentencing Project, an advocacy organization working to end mass incarceration. Some people held pretrial are innocent or have committed only low-level offenses that wouldn’t earn a jail sentence, yet they experience the negative effects of incarceration while awaiting trial.
“Holding them for a couple days, a couple months pretrial has devastating implications for their lives,” Ghandnoosh says. Many find it hard to keep a job, hard to keep their housing. Such outcomes for a minor offense or no offense at all, she says, makes it more difficult to live a law-abiding life and could tip people into crime.
Pretrial detention is especially concerning because it disproportionately affects poor people. While wealthier people can typically post bail to get out of pretrial detention, people in poverty can’t. Pretrial detention also has lopsided impacts on people of color: Black and Latino defendants are more likely to be denied bail or to have their bail set at a higher amount.
Existing research doesn’t address how jail time affects violent offenders, who make up over 40 percent of the total US jail and prison population. When people are convicted of serious or violent crime, they’re almost always put behind bars, which means there aren’t good opportunities to compare the effect of jail time to an alternative sentence for this group.
Still, there’s little reason to think that the effects of incarceration are different for people convicted of violent crime compared to those convicted of nonviolent crime, Petrich says. “We know from other research that people generally don’t specialize in their offending. People just are offenders. They’ll do violent crime, they’ll do property crime, they’ll do drug offending,” he says. “If prison doesn’t work for one group, it’s probably not going to work for another group.”
How to handle borderline cases
Moving away from incarceration altogether isn’t realistic, because the purpose of jails and prisons isn’t just to reduce recidivism but also to incapacitate people who are a public safety risk. “Even if prison doesn’t make them a better person, you’re still stopping them from hurting other people while they’re in prison,” says Robert VerBruggen, a policy researcher at the conservative-leaning Manhattan Institute think tank.
However, the research on recidivism suggests that imprisonment doesn’t make a lot of sense for low-level crimes, and that doing away with it won’t harm public safety, says VerBruggen. “For certain borderline cases, where you have minor offenders, first-time offenders, that sort of thing, you should be careful about incarcerating those people when you don’t need to, because that can make matters worse,” he says.
Policymakers are gradually waking up to the need for change. In the last decade, many states have passed sentencing reforms or release policies to lower their jail and prison populations. The United States still incarcerates a higher percentage of its citizens than any country in the world, but these changes have helped to bring the total jail and prison population in the US down to 1.8 million, as of 2021, from a peak of 2.3 million in 2008.
Even more important than reducing our jail and prison population, though, is improving how we practice incarceration, says Loeffler. He and a growing number of other reform advocates point to rehabilitation in place of punitive sentences, a strategy that is proving successful in other countries. In Norway, for example, rehabilitation — through high school or university education courses, meaningful work opportunities, drug rehabilitation, exercise, art programs and social welfare services — is a key component of life behind bars. A recent study found that spending time behind bars in a Norwegian prison reduces the risk that a criminal will commit future crime by 29 percent.
Many other studies outside of Norway in the last few decades, probing programs from education and work skills to group counseling and drug treatment, have found that rehabilitation programs are quite effective at reducing a prisoner’s risk of future crime. For example, several studies have looked at the effects of educational and vocational programs and have found that they can reduce recidivism by 10 percent or more. Others have examined drug treatment programs and have found reductions in recidivism of 14 percent or more.
Cognitive-behavioral programs, which use individual or group therapy to help people learn to change the thinking patterns that result in destructive or criminal behaviors, appear to be the most effective of all. A study reviewing a range of rehabilitation strategies found that cognitive-behavioral programs in prisons consistently reduce recidivism by 15 percent or more, with some leading to reductions of closer to 30 percent.
It can be tempting to look at the failures of American jails and prisons and conclude that “prisons don’t work and they can never work,” says Loeffler. But there’s plenty of evidence that they can work — with the right approach. “Other countries appear to be practicing incarceration differently and producing improvement in recidivism,” says Loeffler. “What is it we can learn from those places?”