Diagnosing how the U.S. incarceration rate ballooned to 1 in every 100 adults, and prescribing remedies to shrink it, are both frustrated by one central fact: The “system” is actually 51 different systems, each almost entirely independent and driven by its own legal, political, cultural, sociological, and organizational factors. The federal system plays an outsize role because it is the largest and gets the most national media attention. But the 50 states house nearly 90 percent of prisoners, to say nothing of hundreds of thousands of inmates in local jails, and—as the laboratories of incarceration—they must be the main subject of analysis.
Each state has its own criminal code that controls how offenders are sentenced and its own budget that determines the availability of alternatives to incarceration. The variability among states on these and other critical elements of the criminal justice system is breathtaking. In one state, driving with a suspended license is one of the top ten crimes for which people are admitted to prison; in another state, it doesn’t lead to a prison term at all. In some states, more than half of prison admissions are for failing drug tests, missing appointments with probation officers, or other technical violations of the conditions of community supervision. In others, violators are held accountable in day reporting centers or similar noncustodial programs, and almost no one goes back to a state prison cell for rule infractions.
These variations in sentencing and post-release supervision give rise to vast differences in rates of incarceration. At the end of 2014, Louisiana had the highest portion of its population behind bars, with 1,072 per 100,000 adult residents in prison, while Maine was at the opposite end of the scale, with 189 per 100,000 adults. Even geographic proximity is no guarantee of similar rates: North Carolina and South Carolina’s rates were 465 and 552 per 100,000, respectively, while South Dakota at 558 per 100,000 doubled North Dakota’s 278.
Differences in crime rates account for only a small share of the inconsistencies between these pairs of states. The primary explanation lies in the myriad policies, programs, and practices that are set at the state level and interpreted by local prosecutors, defense attorneys, judges, corrections officials, and parole board members. The adoption, enhancement, or repeal of mandatory minimum sentences, for example, is highly dependent on the strength of the political forces on both sides of the debate. If a mandatory sentencing law is in place, local attitudes toward the policy, availability of time on court dockets, and opportunities for alternative programs are major determinants of the extent to which a mandatory prison term will be enforced—or set aside as part of a plea negotiation.
This is not to say there are no national policies or norms that influence how the punishment pendulum swings. There’s little debate that fears surrounding urban unrest in the 1960s and 70s helped cause the rapid growth of U.S. incarceration that Mr. D’Amico describes. The trend was accelerated by the dismantling of large and outdated psychiatric facilities without a commensurate expansion of community services, leaving jails and prisons to house and feed thousands of the mentally ill. In the 1980s and 90s, new federal laws and sentencing guidelines substantially raised the likelihood and length of prison terms for federal offenders and offered billions in grants to states that required violent offenders to remain behind bars for at least 85 percent of their court-ordered sentences.
The new federal statutes transformed the Bureau of Prisons from a sleepy sliver of the Justice Department to a behemoth that chews up nearly one quarter of the department’s budget. But even without the eightfold increase in the federal prison population since 1980, the U.S. incarceration rate would lead the rest of the world many times over. And on the state level, responses to the federal incentives and the “get tough” rhetoric of political campaigns were far from uniform. Between 1995—the first year federal prison-building incentives became available—and 2005, prison populations in five states grew less than 10 percent while jumping by more than 100 percent in four others. The remaining states were spread out evenly in between.
If national phenomena explain only a small part of the explosion in the incarceration rate, they explain only a little more of the recent decline. But from the data we do know this: After reaching a peak of 1 in 100 adults behind bars in 2007–08, the overall rate, which includes local jail inmates as well as state and federal prisoners, has dropped steadily each year since, falling to 1 in 110 adults at the close of 2013. During those five years, 30 states cut their imprisonment rates, while rates in 15 states continued to grow and five were flat.
Many of the states that stopped or reversed their prison growth did so after undertaking an extensive analysis of what was causing the higher incarceration rates in the first place. The reasons then became targets for reform. For many policymakers involved in the reform efforts, one of the surprising drivers of the growth in the prison population was the high rates of incarceration for supervision violators. Specifically, there was a fundamental misalignment of authority and responsibility between state and local governments. In many states, the state government runs and pays for prisons, while local government runs and pays for probation. So if a probationer is causing trouble, local officials can relieve themselves of the cost of supervision—and any potential political fallout—by revoking community supervision and sending the offender to state prison. This dynamic isn’t about punitive attitudes, puritanical culture, or racial bias. It springs straight from the chapters of a textbook on levels of government, separation of powers, and bureaucracy.
Searching for overarching explanations for why the “land of the free” locks up more of its citizens than any other nation is an important exercise. But the size of prison populations the world over is determined by only two factors: the number of people who come into the prison system and how long they stay. In the United States, those factors are determined largely by state policy choices, behind each of which is a unique and tangled story.