About those unintended consequences.

Efforts to give a fair shake to people with criminal records when they apply for low-skill jobs can backfire, substituting instead a racial screen, according to an academic study.

The “ban the box” movement is meant to keep people with criminal records from having their job applications rejected before an employer even sees any of their qualifications. By eliminating the box where applicants with criminal pasts check, activists have hoped to level the playing field – at least giving them a shot for low-skill jobs.

Instead, the result seems to be more rejections of black candidates – whatever their pasts.

According to the study by professors from Princeton and the University of Michigan, many employers are anxious to winnow down the number of applicants for jobs. Deprived of the box, they turn to racial clues, according to the study, referenced recently in a New York Times column by a Harvard economist.

That just hurts the chances of all African-American applicants, wrote Sendhil Mullainathan in the Times.

With “the box” removed, many employers assumed that all black applicants were former criminals and they wouldn’t give a second look to applicants with “black-sounding” names.

"Policy makers can constrain only a few of the large spectrum of choices people make," Mullainathan wrote. "If motives remain unchanged, there remain many unregulated ways of expressing them.

“This is not meant to be an argument for doing nothing,” he wrote. “Instead, it is an argument for picking our battles wisely.”

Postscript: Economist Jared Bernstein argues in a recent piece that the critics of "ban the box" are overstating the case.