WITH budgets under strain, governments across the developed world want to reduce their jail populations. For the first time in decades, America and Europe are now releasing more prisoners than they are locking up. One way to ensure those ex-cons do not wind up back behind bars is to help them find work. But a body of new research suggests one increasingly popular way to promote this has worrying unintended consequences.

Forcing job applicants to declare they have a criminal record—whether or not it is relevant to the post—allows employers to filter out ex-convicts, it is argued, and prevents them finding the sort of work that would help them stay out of prison. So activists across the world have called for “ban-the-box” laws, which prohibit employers from inquiring about criminal histories prior to job interviews or offers.

Some 24 states and many municipalities in America have now introduced laws along those lines. They are also gaining favour in Europe. The British government has banned the question for civil-service jobs; the policy was the core of the previous prime minister’s plans to boost racial equality. As black people are more likely than whites to end up with criminal records—five times more likely in America—banning the box should help reduce bias, advocates say. But research suggests otherwise. Instead, such policies encourage...Continue reading