The U.S. men’s and women’s national soccer teams signed historic union contracts Tuesday that guarantee they will be paid equally. That’s, of course, after the champion women’s team sued the league for gender discrimination in 2019 leading to a $24 million settlement. Under the new contracts, men and women will be paid according to the same pay structure for appearances and tournament games even though FIFA World Cup prize money is still much less for women. The unions agreed to pool those winnings to even things out.

It’s just one example of how collective bargaining can address persistent wage disparities.

They may not have been champion soccer stars, but city workers in San Jose, California, made their mark in 1981 when they held a strike that was a major milestone in the fight for gender pay equity.

“They were able to essentially vote with their feet and say, ‘We’re going to withhold our work.’ And that was what moved the needle there,” said Dalia Thornton with the American Federation of State, County and Municipal Employees. She said the action resulted in $1.5 million of pay increases — largely for women workers.

While the law protects against many forms of discrimination, Thorton said being in a union gives workers more power to do something about it.

“You’re part of something that is bigger than you, you’re part of a group of workers who come together,” she said.

Of course, unions in the U.S. weren’t always inclusive, said William Spriggs, an economist at Howard University and the AFL-CIO. But today he said, union membership confers the biggest pay advantages to women, Black and Latino workers.

“In settings where rules are clear and the playing field is level, then there’s not as much room to discriminate,” Spriggs said.

According to federal data, union membership reduces the gender pay gap by nearly 40%.

“When you’re a member of a union, your pay is controlled by a collective bargaining agreement. There’s transparency around how pay is set, and what people make,” said Emily Martin with the National Women’s Law Center.

And she said union members tend to have better benefits like paid leave that make it easier for women to stay in the workforce and increase their earnings over time.