A new study points to a key way to reduce the prison population in the incarceration capital of the world: boost spending on public mental health.

Reducing the prison population means reducing jail expenditures. The average cost in the U.S. to incarcerate a person is $60 a day, an accompanying press release states.

As the ACLU has written, “The human and financial costs of mass incarceration are staggering.”

For the study, researchers Jangho Yoon and Jeff Luck, professors in the College of Public Health and Human Sciences at Oregon State University, analyzed data from 2001–2009 on 44 U.S. states and Washington, D.C.

They found that while greater spending on public inpatient care and greater spending on community mental health both decreased prison populations, the inpatient spending had a greater return on investment.

A 10 percent boost in per capita public inpatient mental health expenditure on average leads to a 1.5 percent reduction in jail inmates, they found.

“An increase in public inpatient spending would decrease jail populations in the 35 states that spend less than $134 per capita on community mental health care, and the District of Columbia, which also spends less than $134 per capita,” Yoon stated.

Under that amount, “the associated benefit-cost ratio is 26 cents, which indicates a positive intersystem return on investment of 26 percent. Every dollar spent annually on inpatient mental health by a state would yield a positive spillover benefit of a quarter-dollar for the jail system by reducing the number of inmates,” he continued.

As Jamie Fellner, senior advisor for Human Rights Watch’s U.S. program, wrote last year, locking up those who need mental health services can lead to vast rights abuses:

It is well-known that U.S. prisons and jails have become de facto mental health facilities. Hundreds of thousands of persons with mental disabilities spend time behind bars each year, with the surging numbers driven by the limited availability of community-based outpatient and residential mental health programs and resources, the lack of criminal justice diversion programs, and the persistent national problems of poverty and homelessness.

What is less well-known is that most persons with mental illness who are incarcerated face living conditions that at best can be characterized as counter-therapeutic; at worst, they are dangerous. Part of the problem arises from staff use of force. Persons with mental illness in inpatient hospitals are not at risk of needless or punitive beatings, assault with pepper spray, or being stunned with conductive electrical devices. But those in jails and prison are.

A 2014 report from the National Research Council, which noted the “historically unprecedented and internationally unique” boom in incarceration rates, said that “64 percent of jail inmates, 54 percent of state prisoners, and 45 percent of federal prisoners report[ed] mental health concerns,” the American Psychological Association noted.

“Part of what’s really swelled our jail and prison population, especially our jail population, is our inability to deal with the mental health crisis that we’re facing in this country,” June Tangney, a psychology professor at George Mason University who studies offender rehabilitation, said at the time. “We have an enormous number of people who are suffering from very treatable illnesses who are not getting treatment and who end up getting caught in the criminal justice system as opposed to the mental health system.”

Originally published at CommonDreams.org by Andrea Germanos, staff writer