For years, policymakers have tried to find the best ways to support ex-offenders as they re-enter society. One idea that’s gained momentum in recent years: “ban-the-box” laws, which bar employers from asking applicants about their criminal history when they first apply for a job. Backed by a broad coalition of interest groups ranging from the liberal-leaning National Employment Law Project (NELP) to the conservative American Legislative Exchange Council (ALEC), a flurry of jurisdictions have enacted these measures. The thought is that when questions concerning criminal records are delayed until later in the hiring process, ex-offenders have a better shot at being hired based on their qualifications.

Nearly half of states and more than 100 localities now have some form of a ban-the-box law on the books. Most of them cover only public employers or government contractors. But nine states have taken it a step further, barring private employers from asking about criminal records on applications.

Until this year, there was little research into the effect these laws actually had. But a pair of recent studies suggests they carry an alarming unintended consequence: Young African-American men without criminal histories, an already disadvantaged demographic, may find it even harder to receive job callbacks.

In one study, University of Michigan researchers submitted 15,000 fictitious job applications before and after ban-the-box policies went into effect in New Jersey and New York City. Using distinctive applicant names to imply race, they measured whether employers either requested an interview or asked applicants to call them back.

Employers contacted all black applicants at a rate of 11 percent following enactment of the policy. That’s an improvement for blacks with convictions, but a decline for those with clean records, who had previously received callbacks at a rate of 12.7 percent. The study was limited to applicants ages 21-22 during a few months immediately after ban-the-box became effective.

If there’s good news, it’s that the study found strong compliance with the laws, essentially eliminating the initial hurdle ex-felons face. “Weighing that advantage versus the increase in racial discrimination that we find is a difficult policy dilemma,” says report author Sonja Starr.

Another study, published by the National Bureau of Economic Research in July, suggests that young black men without college degrees were on average 3.4 percentage points less likely to be employed under ban-the-box, and young Hispanics were 2.3 percentage points less likely to be working. For those without a high school diploma or GED, the discrepancies were even greater.

The study, which controlled for region-specific employment shocks and individual characteristics, also found larger unintended effects when unemployment was high. The negative effects further worsen over time: Five or more years after enactment of ban-the-box, the likelihood of employment for young black men without college degrees had declined an average of 7.7 percentage points. By contrast, the effect on young Hispanics diminished over time. Jennifer Doleac of the University of Virginia, who co-authored the study, suspects this is because Hispanics work around the law by relying more on networks of friends and relatives to find jobs.

The two studies reached similar conclusions despite using different methodologies and outcome measures. But ban-the-box supporters dispute the findings, contending that the laws are effective.

Both NELP and ALEC question an assumption in Doleac’s study that considered individuals to be affected by the policy if their state or any jurisdiction within their metro area had any type of ban-the-box law. This meant that private-sector employees were counted as affected even if the law applied only to the public sector. In the District of Columbia, where a ban-the-box law covers all local government and private employers, a recent audit reported that a majority of private employers surveyed said they had not been adequately informed of the law. “Both ban-the-box studies should be scrutinized more closely before their findings are considered indisputable,” says Ronnie Lampard, who heads a criminal justice reform task force for ALEC, which supports public-sector ban-the-box policies.

Ban-the-box supporters also point to positive benefits for other demographic groups. In Doleac’s study, older black men without college degrees and college-educated black women were more likely to be employed under ban-the-box, regardless of whether they had criminal records. “Overall, the net benefits seem to outweigh the negative impacts these studies are purporting to document,” says Beth Avery, a NELP attorney. “We’re not ready to give up on these policies that are really making a difference in the lives of those with criminal records.”

What’s not subject to debate is that the laws clearly help many offenders overcome steep barriers to employment. A review of ban-the-box policies in Durham, N.C., found that the share of city government hires with criminal records increased sevenfold after the laws took effect from 2011 to 2014. A recent D.C. audit report on ban-the-box similarly found year-over-year increases in hiring of applicants with criminal backgrounds for most agencies reviewed.

One early adopter, Seattle, is tracking violations of its ban-the-box law, but hasn’t yet studied its effects since its implementation in November 2013. “We haven’t come up with any policy changes based on what emerged from the studies, but we are taking a close look at them to see if we need to adjust any policies or protocols,” says Elliott Bronstein, spokesman for the city’s Office of Labor Standards.

Authors of the two new studies say they’ve yet to hear of any states or localities considering overhauling their laws as a result of their findings. “It’s more likely that this kind of research will be taken into account in jurisdictions that haven’t done this yet or gone the full distance,” Starr says. Doleac, however, has called on jurisdictions to repeal their laws and seek better alternatives, such as ensuring that employers consider the full context of an applicant’s conviction.

It’s already illegal for employers to reject applicants on the basis of race or issue blanket hiring bans on ex-offenders. But pushing some employers to change longstanding behaviors is easier said than done. “These studies just highlight existing racial bias,” NELP’s Avery says, “and that is the real problem.”