The United States has a prison population like nowhere else. With one out of every 100 adults behind bars, our incarceration rate is the highest in the entire world. Our inmates—1.5 million in prison, with another 800,000 in jail—comprise one-third of the world's total. This is a surprisingly recent development. After barely budging for 50 years, our incarceration rate increased sevenfold (to 738 per 100,000 people) between 1978 and 2008.
The system is now at its breaking point. Federal judges in California just issued a tentative order demanding that the state release nearly 60,000 inmates over the next three years to alleviate intolerable overcrowding. New York state's sentencing commission released a 326-page report calling on the Legislature to cut back on severe drug sentences. And with budgets growing ever-tighter in a collapsing economy, states are beginning to realize that large prison populations are boom-time luxuries they can no longer afford.
Reform is inevitable. But if we are going to rein in our prison populations, we should do so based on facts, not on unfounded perceptions or shocking anecdotes. So let's start by dispelling some of the myths that surround the breathtaking prison growth of the past three decades.
Myth No. 1: Long sentences drive prison population growth. The stories that capture our attention are the low-level crooks who get 25 years for stealing three $400 golf clubs. But these cases get a lot of press precisely because they are exceptional. And the attention goes to the sentence imposed, not the time actually served, which may be far shorter.
Our data on time served is imperfect at best, but it appears that the time served by the median prisoner is about two years, sometimes much less. It is easy to focus on the people who are serving decades-long sentences for life or life without parole, but they make up only about 10 percent and 2.5 percent of the total prison population, respectively. The two-year median, meanwhile, holds true both in notoriously punitive states like Michigan and in more lenient ones like Minnesota. Not only is the absolute amount of time served low, in general, but in many states that amount remained flat over much of the 1990s.
So what is actually driving prison population growth? Admissions. Far more offenders who in the past would have received nonprison sentences are being locked up for short stints, driving up the overall population. Stop admitting as many people, and the prison population would shrink rapidly. Cutting back on long sentences is far less likely to have the same meaningful effect.
Myth No. 2: Low-level drug offenders drive prison population growth. It is popular, perhaps almost mandatory, to blame the boom on the War on Drugs. But it is just not true. Only 20 percent of inmates in prisons (as opposed to jails) are locked up for drug offenses, compared with 50 percent for violent crimes and 20 percent for property offenses; most of the drug offenders are in prison for distribution, not possession. Twenty percent is admittedly much larger than approximately 3 percent, which was the fraction of prisoners serving time on drug charges in the 1970s. But if we were to release every prisoner currently serving time for a drug charge, our prison population would drop only from 1.6 million to 1.3 million. That's not much of a decline, compared with the total number of people in prison in the 1970s—about 300,000.
In fact, the war on drugs does play a role in the prisoner increase. But it's an indirect one. State "predicate felony" laws, for example, impose longer sentences on offenders with prior records: A drug conviction may not send someone to prison, but it will make him serve more time for any future crime he commits. This suggests that simply tackling long drug sentences, as reformers in New York state have done, may miss the real problem.