Jailing Efficiently—and Less Often

Deciding which arrestees to keep in jail while they await trial is one of the more difficult and arbitrary tasks facing judges. Under-incarcerate arrestees and they may disappear, endanger witnesses or victims, or commit additional crimes that harm the community. Over-hold arrestees and you may cause innocent parties or minor offenders to lose their jobs, have a hard time preparing their defense, or endure unnecessary stress while locked up awaiting trial.

In 2015, the Laura and John Arnold Foundation rolled out a new tool to make this judgment easier, fairer, and more efficient. The tool was developed by studying the actual results of 1.5 million cases across the country, and it allows judges to enter the charge, criminal history, and age of the arrestee, then get a scientific, real-life assessment of the wisdom of either holding him or letting him remain at home until trial. This avoids subjective unfairness, jailing’s potentially toxic effects on people’s lives, and unnecessary taxpayer expense for housing inmates.

During the past 20 years the average stay for a jail inmate has grown from 14 days to more than three weeks. Pilot tests of the new Arnold tool show that it will reduce jail populations by about 20 percent. The foundation has offered to provide the tool for free to any city, county, or state that would like to have it available. In 2015 it was introduced in 29 jurisdictions—including three large cities (Chicago, Charlotte, and Phoenix) and three entire states (Arizona, Kentucky, and New Jersey).

Both local jail and federal prison populations have peaked—jail numbers started declining in 2008, and prison levels topped out in 2013. But a number of philanthropies have expressed interest in further speeding deincarceration. The John and Catherine MacArthur Foundation announced in 2015 that it was dedicating $75 million to help local jurisdictions find ways to reduce jail populations. It granted $150,000 to 16 counties, three cities, and one state to help them develop ideas for reducing jailing, with follow-up grants of up to $2 million promised so half of them can put their plans into action. The foundation also funded academic research on alternatives to sending people to jail.