Women earn 79 cents for every dollar brought home by men — and according to advocates for wage gap reform, that system of inequality follows employees from job to job thanks to one common interview question: “How much was your previous salary?”

Philadelphia wants to fix that. On Monday, Mayor Jim Kenney signed the Wage Equity Law, which prevents employers from asking about an applicant’s previous pay, the Philadelphia Inquirer reports. The mayor’s signature made Philadelphia the first city in the nation to institute such a ban. It will become law in May.

The mayor pushed the bill forward despite arguments from local businesses, who have threatened a legal challenge.

“The Law Department has thoroughly reviewed the legal concerns raised by the business community, and is confident that the law would withstand a challenge and the city would prevail,” Kenney said, according to Inquirer.

In a letter published by the Philadelphia Business Journal earlier this month, the city’s chamber of commerce president and CEO Rob Wonderling raised several concerns about the bill. While he supports ensuring “wage equity among all people” and recognizes “long-standing issues regarding underpayment of minority and female employees,” he believes that the wage ordinance as written is “an overly broad impediment to businesses seeking to grow their workforce in the City of Philadelphia.”

“When employers look at a candidates’ salary history, they have a better understanding of whether a candidate is worth pursuing based on previous compensation levels as well as the market value or salaries for comparable positions,” he wrote.

Despite the business community’s hesitation, City Council passed the bill in December 16-0, the Inquirer reports. It’s not the only city tackling the pay gap — earlier this month, Boston released a report on local wage inequality, along both gender-based and racial lines. The report is a first step toward leveling the salary scale.

“We had two options: Ignore the gender wage gap and hope it goes away over time (data tells us that we will reach equity by the year 2152) or do something about it,” Mayor Marty Walsh wrote in a letter at the start of the new report.

That report followed national statistics in its finding that women of color were particularly poorly represented in some aspects of the local pay scale.

“It is especially critical to our mission that we lift up multicultural women and help businesses build work environments where diverse women can thrive,” Carol Fulp, president and CEO of The Partnership, Inc. wrote in the report.

Rachel Dovey is an award-winning freelance writer and former USC Annenberg fellow living at the northern tip of California’s Bay Area. She writes about infrastructure, water and climate change and has been published by Bust, Wired, Paste, SF Weekly, the East Bay Express and the North Bay Bohemian

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