With 2.2 million people behind bars the United States has become the world’s leading jailer. Nearly 5 million more people are on probation or parole.

Although the Bureau of Justice Statistics reports that the prison population in 2012 declined slightly, for the third straight year, inmate counts rose every year between 1973 and 2010. Sentencing reforms and policy changes are needed to bring prison populations back to rational, sustainable levels.

The rising incarceration numbers were driven by policy changes — not crime rates — including harsh mandatory minimum sentences for drug offenders, so-called three-strikes laws and other get-tough measures.

Nearly half of state-prison inmates in 2011 were convicted of nonviolent drug, property or public-order crimes, according to the bureau. The nation needs, among other things, shorter but more intense prison stays for many probation and parole violators and parole opportunities for the growing number of aging and sick inmates.

In recent years, a growing number of activists, policymakers and politicians — including budget-conscious conservatives — have questioned the prison-building boom. Today’s prisons are big business and come with a big price tag, $75 billion a year.

Mass incarceration has severed community social networks, especially in poor neighborhoods, left one in 14 African-American children with a parent in prison and created lifelong employment barriers for the 95 percent of prisoners who eventually go home.

The United States has much to gain by ending its insidious, costly incarceration spree. By having the courage to right-size prison populations, state and federal officials can transfer the billions of dollars wasted on warehousing inmates and spend them on education, transportation and other vital needs.

First Published: January 20, 2014, 5:00 a.m.