Across the United States, men outearn women in comparable jobs by 15%, Meanwhile, white employees outearn their Black peers by 11%, even after accounting for such differences as education, experience, occupation, industry, region, hours worked, and union coverage says Jim Bessen, executive director of the Technology & Policy Research Initiative (TPRI) at Boston University’s School of Law.

These stunning facts beg the question: what can we do to close wage gaps? According to a new paper, one way is to ban employers from asking about salary history.

The paper, which is not yet peer-reviewed, looks at the effects of salary history bans in the 14 states that have passed laws prohibiting employers from asking prospective hires about their past pay.

In a report of their new findings, Bessen and his team write, “Salary history reveals information about the applicant’s reservation wage”—the wage they are willing to accept—” that might give the employer a bargaining advantage. Job applicants currently suffering from discrimination or other inequities might well be willing to accept a lower wage offer than other workers with comparable capabilities.”

But discrimination can’t be blamed fully for wage differences, the study authors say: “For instance, they might reflect group differences in negotiating propensity. But salary histories enable a form of institutional discrimination. Even if employers do not individually discriminate, the use of salary histories appears to perpetuate the effects of past discrimination or other group inequities.” That makes salary histories “a target for policy change,” the researchers conclude.

If a peer review maintains the validity of this study, then surely it’s time we ban employers from asking about salary history in all states.