IF THERE IS a silver lining to financial crises it is that governments may consider sensible policy changes that were once politically off-limits. Such is the case with prison reform.

State spending on corrections has quadrupled over the past two decades, making it the fastest-growing budget item after Medicaid, according to the Vera Institute of Justice, a nonprofit organization that works with governments on criminal justice policy. In the early 1970s, there were 250,000 inmates in the United States; today, that number is 2.4 million, the result of inflexible sentencing policies that have made the United States the world’s leading jailer.

This penchant for throwing away the key no doubt has been a factor in the decreasing rates of violent crime, but it comes at a steep price. A December 2011 analysis by the institute of 40 state budgets concluded that they spent a total of $39 billion on corrections each year. There are better and more cost-effective ways to protect public safety.

Between 1999 and 2009, New York saw a 30 percent reduction in violent crime, far outpacing the 5.4 percent dip in other states. This decline occurred as the state reduced its prison population by 18 percent. The state achieved these remarkable results by reforming its sentencing laws to eliminate or substantially reduce prison terms for nonviolent offenders. Not only did this slow or stop the flow of imprisonment of low-level offenders, it also better ensured that space would be available for those who presented a true threat. New York also increased the amount of “good time” credits to allow prisoners to earn early release. Even traditionally tough-on-crime states such as Texas and Mississippi have adopted or are moving toward similar changes.

The Justice Department, too, is embracing reforms to reduce the number of federal nonviolent offenders who are placed behind bars and to better ensure smooth transitions for those who are imprisoned and released. In its recent budget request – which kept Justice funds essentially flat – the department signaled it would be more assertive in urging courts to offer “compassionate release” to seriously ill inmates. The department should use this legal authority also to urge freedom for the growing ranks of elderly prisoners who no longer pose a risk. Acknowledging that one-third of prisoners are behind bars for parole violations, the department smartly requested small funding bumps for drug rehabilitation programs that have proven helpful in giving drug-addicted inmates a chance at successful re-entry.