Originally posted at the Public Policy Institute of California.
By Magnus Lofstrom and Brandon Martin.

Two major criminal justice reforms—realignment and Proposition 47—have brought California’s incarcerated population down to levels not seen since the mid-1990s. This drawdown in both the state prison and the county jail populations addresses some of the serious capacity challenges the systems have faced.

As of August 2015, the total prison population had dropped by almost 45,000 inmates from its 2006 peak. The majority (about 55%) of the decline was a result of realignment, which was implemented in October 2011 in response to a court order to improve prison conditions by reducing overcrowding. However, it took the passage of Proposition 47 last November—which reclassified a number of felony drug and property offenses as misdemeanors—and building and renting additional prison beds to reach the court-ordered population target of 137.5 percent of design capacity. The prison population has declined by almost 7,700 since November and has remained below the mandated target since January 2015. This is a key requirement for the state to regain control over prison health care—currently, a court-appointed receiver oversees health care in the system.

Proposition 47 appears to have relieved some of the pressure on county jail systems created by the shift of responsibility for lower-level offenders from the state to the counties during the first few years of realignment. The average daily jail population dropped by almost 10,000 inmates after the passage of Proposition 47 last November. As of December 2014, there were about 72,500 inmates in county jails, down from about 82,000 in October. This brought the jail population back under the statewide rated capacity of nearly 80,000 beds. Another sign that Proposition 47 has relieved some pressure is that the number of inmates released early due to housing constraints decreased noticeably (by almost 20% as of December 2014 compared to December 2013), to levels well below those observed in the months before realignment was implemented.

Although we can see that prison population numbers have dropped in each of the nine months since Proposition 47 passed, we need to be more cautious about the measure’s impact on jail population numbers because we only have jail data for the first two months. Also, counties have been working to implement and refine new jail policies and procedures, and these may be having an impact on jail populations. For instance, data through March 2015 for Los Angeles County show that the jail population dipped below 16,000 inmates in December (down from more than 18,000 in October), but rose above 17,000 in January and stayed above 17,000 through March. This increase is related to the sheriff requiring that inmates serve a larger percentage of their sentences before release. We may see similar developments in other counties. Nonetheless, even in Los Angeles there was a noticeable drop in the jail population compared to months before passage of Proposition 47.

Clearly, California is moving away from incarceration, in line with research that has shown that incarceration is not a cost-effective tool for crime prevention, at least not at the high levels in the state before realignment. The changes implemented so far may help improve prison and jail conditions and may also help the state and counties handle their corrections responsibilities more effectively. However, research also suggests that there may be a greater upward pressure on crime with incarceration reductions at lower levels of incarceration, which heightens the need to identify and implement effective crime preventive strategies. As we continue to monitor crime trends, it will be important to determine whether their long-term decline has been reversed.