Gov. Arnold Schwarzenegger of California was on the mark when he said this week that the state needed to change policies that spend more money on prisons than on the state’s once-vaunted higher education systems, which are being bled to death in budget cuts. But Mr. Schwarzenegger was way off the mark when he suggested that the answer was to privatize prison services or to pass yet another constitutional amendment, this time to limit prison spending.

States that privatize prisons sometimes save money, but they can also buy trouble by ceding control to companies that put profit first and inmate welfare a distant second. That would be disastrous for the California prison system. It is already under pressure from scores of court orders that require it to reduce its growing prison count and provide adequate mental, medical and dental services, as well as better care for the disabled.

It would generally be impossible for the state to unilaterally lower prison spending without first cutting the prison population dramatically. And because so much prison spending is nondiscretionary, a constitutional amendment that reduced spending  without cutting the prison population  would be doomed to failure. It would also draw the ire of judges who have rightly run out of patience with the state’s long list of failures in this area.

The only real way for California to cut prison costs is to reverse sentencing policies that have filled its prisons to bursting and have driven up costs by about 50 percent over the last decade alone. Among other things, too many minor offenders are sent to jail for too long.