In recognition of the Department of Labor’s centennial, we recently launched “Books that Shaped Work in America,” an initiative that invites the public to weigh in on how books have influenced and reflected the changing nature of the nation’s workforce.

My colleague Sharon Block recommended The Girls in the Balcony: Women, Men, and the New York Times, which chronicles the struggle for equality by female Times employees in the 1970s. By demonstrating how pervasive and entrenched discrimination can be, Block says, the book “validated my mother’s fears that women cannot take any opportunity for granted.”

That understanding is at the heart of the equal pay enforcement program at the Office of Federal Contract Compliance Programs. And over the past four years we’ve made good progress. We have implemented many recommendations of President Obama’s Equal Pay Task Force. We have eliminated outdated guidance that posed barriers to the agency’s enforcement work. And we have recovered back pay for workers – many of whom did not even know that they were being unfairly underpaid until we reviewed their workplaces.

Since the president established the Equal Pay Task Force in January 2010, OFCCP has resolved over 90 cases of pay discrimination and recovered approximately $3.3 million in back wages and salary adjustments for more than 1,400 workers. About one-third of our successful settlements now involve issues of pay discrimination – while in prior years the agency was only addressing a handful of such cases annually.

Some highlights include:

• A $250,000 settlement in 2011 on behalf of 124 female pharmaceutical sales workers at AstraZeneca, who were paid on average $1,700 less than their male counterparts, and an agreement that the company would review pay practices and make needed adjustments.

• A $290,000 settlement in 2013 providing back pay to 78 Hispanic production workers at Medtronic’s facility in Danvers, Mass., who were paid less than comparable White workers performing the same job.

• A 2013 agreement by G&K Services Co. to pay over $265,000 in back pay to 58 female laundry workers who were steered into lower paying positions based on stereotypes about the kinds of work women and men should perform.

I’m proud of the accomplishments my staff has made in this area, but we still have work to do. We have just begun to implement our new investigative guidance. We are also on the verge of completing a national training program for all OFCCP investigators. I expect that over the next year this more robust and effective approach will improve our ability to identify systemic pay discrimination, which under the old guidance was a relatively small component of our enforcement work.

We have also committed to providing more compliance assistance tools to make it easier for employers to proactively review their pay practices, and ensure fair and equitable compensation for all their workers.

Finally, the Equal Pay Task Force has clearly identified the need for more and better data to support enforcement, and so we have made addressing that knowledge gap part of our agency’s regulatory agenda. In 2011, we asked stakeholders for input on an Advanced Notice of Proposed Rulemaking. In a 2013 report, the Equal Pay Task Force identified this as a continuing area of interagency collaboration. In a world where pay secrecy prevents workers from exercising their rights, a compensation data collection tool could provide essential information to help level the playing field.

We are also engaged in non-regulatory approaches that empower workers with knowledge, like our partnership with the department’s Women’s Bureau and other agencies for the 2012 Equal Pay App Challenge.

Looking back, there is no doubt the equal pay enforcement program at OFCCP is making progress. Our investigators are better equipped, our agency has new partnerships, our work in this area continues to grow and improve. And that progress is important, because the gender pay gap has real consequences for workers and their families.

So we will continue pushing forward. We will continue to enforce the laws that require fair pay without discrimination. And we will ask contractors to partner with us on the progress still to come.

Patricia A. Shiu is the director of the Office of Federal Contract Compliance Programs.