It costs about $50,000 a year to lock someone up in a California prison or a county jail — more than 10 times the state’s per-pupil expenditure for public education.

Despite investing hundreds of billions of dollars in new prisons and jails over the past 30 years, California’s correctional facilities are crowded beyond capacity. The state is under a federal court order to reduce its prison population. And after assuming more responsibility for corrections, many counties are releasing inmates early, either under court orders or self-imposed caps on jail crowding.

Building prisons isn’t the answer. But putting fewer people behind bars might alleviate the problem.

Some experts have argued for years that a small investment in education, mental health and crime prevention programs would produce big savings on incarceration. But that’s a long-term strategy in a state with upwards of 190,000 inmates in its prisons and jails.

So the state corrections budget climbed to $9 billion a year. Meanwhile, cheered on by police, prosecutors and the union representing the state’s prison guards, voters and legislators enacted increasingly harsh sentences — and not just for violent crimes. That fueled the need for new prisons and a costly culture of recidivism.

There’s an opportunity to try prevention on a wide scale.

Proposition 47 on the Nov. 4 ballot would reduce sentences by redefining several nonviolent offenses as misdemeanors, including petty theft, receiving stolen property, writing bad checks and simple possession of drugs. About 40,000 people are convicted of those offenses annually .

Shorter sentences would result in savings of several hundred million dollars a year for state and local governments, the state’s nonpartisan legislative analyst said.

Proposition 47 earmarks 90 percent of those savings for truancy prevention and mental health and substance abuse treatment — programs that keep people out of the justice system by helping them lead productive lives. The rest of the savings would go to programs for crime victims.

The initiative is sponsored by former San Diego police Chief Bill Landsdowne and George Gascon, the district attorney and former police chief in San Francisco.

The opposition also comes from law enforcement, with organizations such as the California State Sheriffs Association and the Fraternal Order of Police arguing that only stiff sentences will ensure public safety.

But this initiative doesn’t reduce sentences for violent criminals. Moreover, a lack of substance abuse programs — inside and outside the prisons — is a major contributor to the state’s high rate of recidivism.

As Gason told KTVU, “The reality is all these people who we have been arresting for drug possession are coming out of prison very early and are re-offending because we are not dealing with the basic problem.”

California voters started restoring some balance to criminal penalties two years ago with a measure that limited life sentences under the three-strikes law to violent offenders. Proposition 47 is the next step, redirecting resources from incarceration to prevention. Keeping kids in school and treating substance abuse and mental health issues will keep people out of prison. The Press Democrat recommends a yes vote on Proposition 47.