Serving Time in Overcrowded Prisons Makes Ex-Cons More Likely to Reoffend

A new study finds that inmates at severely overcrowded prisons are two and a half times more likely to violate their parole.

Inmates at Men state prison in Chino, California.
Inmates walk around a gymnasium where they are housed due to overcrowding at the California Institution for Men state prison in Chino, California, on June 3, 2011.

Photo by Lucy Nicholson/Reuters

Criticism of mass incarceration falls roughly into two strains of thought. The first says that imprisoning more than 1.5 million people, and jailing 800,000 others, is a moral disaster. The second says it is a practical disaster, costing taxpayers dearly while destabilizing communities and doing little to lower the crime rate.

The problem of prison overcrowding is usually raised in service of making the first point. Overcrowding, the argument goes, contributes to America’s so-called correctional facilities being hellholes of human suffering. That was the gist of the Supreme Court’s 2011 ruling in Brown v. Plata, which said that overcrowding levels in California prisons—where the average occupancy rate across all state institutions was 187 percent from 1991 through 2010—amounted to a form of cruel and unusual punishment. 

That argument might not be persuasive to people who have a hard time feeling sorry for convicted criminals. But the results of a new study suggest it’s not the only argument against overcrowding: It turns out that people who have served time in severely overcrowded prisons are much more likely to violate their parole after their release. That means they are more likely to be rearrested and to end up back in prison, forcing the government to spend more money on them in the process.

Michael Ruderman, the Touro University doctoral student in medicine and public health who conducted the study, explained the findings by saying that overcrowding might expose prison inmates to added “psychosocial stress” and poor addiction treatment, both of which are known to make people more prone to impulsive behavior, aggression, and drug use.

Ruderman arrived at his conclusions, which were published in the journal PLOS One, by tracking former prisoners in California who were on parole between January 2003 and December 2004. After selecting a random sample of about 13,000, he used monthly reports from the California Department of Corrections and Rehabilitation to look at whether there was an association between people’s likelihood of violating their parole and the average level of overcrowding in the part of the state where they did their time. (Ruderman explained that he aggregated the prison crowding levels by region, instead of using data on individual facilities, because of how the data was collected; this is acknowledged in the paper as one of the study’s limitations.)

Ruderman split the regions into three categories, based on the average levels of overcrowding in the prisons located there: those with an occupancy rate of less than 190 percent of their capacity were in the “low” category, those between 190 percent and 205 percent were “medium,” and those with 205 percent and higher were “high.” What Ruderman found—after controlling for a variety of risk factors, including sex, race, mental health status, and number of serious prior offenses—was that the people in regions with “high” overcrowding were 2.52 times more likely to violate their parole than the ones from regions with “low” overcrowding.

The effect was particularly strong when Ruderman looked at specific types of parole violations. Cases in which the parolee failed to show up for a meeting with his parole officer or left the state’s jurisdiction without permission were 3.56 times more likely to involve people from regions with “high” overcrowding as “low”; people whose violation centered on drug use, drug possession, public drunkenness, or another “Level 1” transgression were 2.44 times more likely to come from regions with “high” overcrowding as “low.”

It’s important to note that Ruderman’s study only establishes an association—not necessarily a causal link—between overcrowding and parole violation. But it makes intuitive sense that prisons where resources are stretched especially thin do a worse job of delivering services to inmates suffering from mental health and drug problems, and that inmates who suffer from those conditions would be more likely to end up getting in trouble once they’re free if they don’t receive the treatment they need while they’re in prison.   

“In severely overcrowded facilities, you no longer have the ability to protect inmates from sexual assault and physical abuse, and you’re depriving people of basic services like medical care,” said Ruderman in an interview. “All these things make the most marginalized, most vulnerable people in society that much more vulnerable.”

It should be said that the problem of prison overcrowding in America is already being taken seriously—nowhere more so than in California, where the prison population has dropped considerably since 2009, when a federal court ordered the state to reduce overcrowding levels to 137.5 percent of capacity. But Ruderman’s study gives critics of mass incarceration—especially those who don’t want to be seen as coddling criminals—one more compelling piece of evidence for their argument.