The United States leads the world in many categories that evoke pride and one that should not: We lock people up at a higher rate than any other country. We also have a lot of ex-offenders who have a hard time finding legitimate work. And an ex-offender with no job and no money is a crime waiting to happen.

But a few years back, we came up with a remedy for that problem: forbidding employers from asking applicants about their criminal records at the start of the hiring process. Only after candidates have been found qualified and offered interviews may the employer request this information.

Illinois and dozens of other states have enacted “ban the box” laws to improve the job prospects of correctional alumni. (The term refers to the square you check if you have a criminal record.) In December, President Donald Trump signed a measure imposing a similar rule on federal agencies and contractors. These laws are particularly relevant to black men, who have far higher rates of imprisonment than other men — and higher unemployment rates.

Even in today’s hot job market, African American men from age 20 to 34 are twice as likely to be out of work as their white peers. Ex-offenders are typically five times likelier to be unemployed than other people. Their neighbors would be safer if those ex-offenders could find steady jobs that would divert them from felonious activity.

Banning the box was a plausible reform. “This law will help ensure that people across Illinois get a fair shot to reach their full potential through their skills and qualifications, rather than past history,” said Illinois Gov. Pat Quinn when he signed the bill in 2014. The assumption was that if ex-offenders could clear the initial screen, employers would be more likely to excuse their past transgressions.

But all these changes in state laws didn’t account for a powerful and immutable law: the law of unintended consequences. The evidence about banning the box is piling up, and it’s not pretty. Instead of helping ex-offenders and black men, they have backfired on both.

Last year, Jennifer Doleac, an economics professor at Texas A&M who is affiliated with the University of Chicago Crime Lab, gave written testimony to a U.S. House committee on these laws. Her conclusions were sobering.

“Current evidence suggests that Ban the Box may not increase employment for people with criminal records, and might even reduce it,” she said. “Delaying information about job applicants’ criminal histories leads employers to statistically discriminate against groups that are more likely to have a recent conviction.” In a triumph of perversity, the people who were supposed to gain ended up worse off.

The latest evidence, assembled by University of California, Santa Barbara, economist Ryan Sherrard, confirms the detrimental consequences. After such a law is passed, his study found, African American men get fewer job callbacks — and white applicants get more. In places that “ban the box,” black ex-offenders are likelier to end up back in jail than before.

The reasons for these unwanted results are not hard to guess. When employers can’t find out whether applicants have criminal histories, they don’t assume the best about black men; they assume the worst.

An employer who would hire an unskilled young African American man who has never been in trouble, but not one with a rap sheet, can no longer tell one from the other until late in the process. The applicant with a spotless record has no way to distinguish himself from the onetime Gangster Disciple.

So hiring managers may decide to avoid the hassle by not considering many, or any, young black men. Under “ban the box” laws, employers seem to develop a greater preference for white candidates.

This effect works to the disadvantage of African Americans who haven’t been in trouble with the cops. It’s also no favor to those who have. Sherrard thinks the increase in recidivism may stem from the discouragement that arises when an ex-offender gets a callback and an interview, only to then be rejected because of his past. Raising false hopes is corrosive.

Doleac offers a few alternatives to make it easier for former inmates to get jobs, including education and training to improve their skills, authorizing judges to issue them certificates of work readiness and giving employers legal protection if such employees commit crimes on the job.

But the priority should be to repeal these laws, which have hindered the people they were meant to help. Sometimes the best way to do good is to stop doing harm.

Steve Chapman blogs at http://www.chicagotribune.com/news/opinion/chapman. Follow him on Twitter @SteveChapman13 or at https://www.facebook.com/stevechapman13. To find out more about Steve Chapman and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.