Michigan plans to overhaul its jail system

WHEN CRIME rates were last as low as they are today in Michigan, the Beatles topped the charts with “Hey Jude”. Half a century on, Michigan’s police arrest fewer people with each passing year. In the decade to 2018 arrests fell by one-fifth. One might expect, in turn, the state’s jails to be eerily empty. Quite the opposite. A new study by Pew Charitable Trusts found 16,600 people were held in county jails on an average day in 2016, over three times more than in 1970.

This fits a nationwide pattern. Even as crime rates and the number of arrests fall, jail populations in many states remain high. County-run jails are the front end of America’s criminal-justice system, where more people are put behind bars than are ever thrown into prison. (Jails house people who are awaiting trial, whereas prisons are typically for locking up felons.) In 2017 jails nationally handled 10.6m admissions, compared with just 607,000 who went into the country’s prisons.

That is good for nobody. Crowded jails are a financial burden for counties. It cost $478m to run Michigan’s in 2017. Pew researchers point to evidence that people jailed or imprisoned, even briefly, are far likelier to be rearrested within two years than others who pass through the justice system but are not locked up.

If America is to put fewer people behind bars, the...