California prisons have operated at around 200 percent of capacity for more than 11 years. This has resulted in rapidly increasing costs: in 2011, the state budget included $9.8 billion for corrections, an increase of about 300 percent from 1991. Corrections expenditures now consume 11.2 percent of the state's general fund, up from 6.7 percent in 2001.
While much attention has been focused on California's “three strikes” law and its high parole recidivism rate as the sources of prison growth, a far less well known driver of prison admissions has been the probation system. In 2009, the California Department of Corrections and Rehabilitation (CDCR) estimated that 40 percent of new prison admissions in the past year were revocations from probation. Not only does the state have a large probation population (around 330,000 probationers in 2010), but California probationers had a 10 percent lower rate of successful completion than probationers in other states.
Probation is administered by California's 58 counties. However, with limited funding available from county governments, probation departments typically have had few resources to improve community supervision. They also have had little incentive to do so: troublesome probationers could be revoked to state prison, relieving the counties of the cost of supervising them and the political liability of any future crimes they might commit.