The pay disparity between men and women is lower among union members than among American workers as a whole but it still exists, according to a new analysis of data released Wednesday.

Culling figures from the Census Bureau and Labor Department, among other sources, researchers from the non-profit Institute for Women’s Policy Research (IWPR) found that women in labor unions “earn 88.7 cents on the dollar compared with their male counterparts, a considerably higher earnings ratio than the earnings ratio between all women and men in the United States."

As of 2013 women overall earned roughly 78 cents on the dollar compared to men, according to an April report from the White House’s Council of Economic Advisors. The IWPR report found that unionized women make 30.9 percent more than their non-union counterparts on average, among full-time workers.

IWPR study director Ariane Hegewisch, one of the report’s authors, said unionized women derive other benefits as well.

“Particularly with issues that happen to be in the news lately, such as scheduling predictability, and health and safety, there’s an advantage for women to be in unions,” Hegewisch told Al Jazeera.

Prior research has found that unpredictable work hours — something less common in unionized shops, where collective bargaining contracts often regulate schedules and mandate overtime pay — put particular stress on women, because they tend to assume a disproportionate share of the childcare and housekeeping duties outside work.

While unionization was found to soften workplace inequities, it does not eradicate them; the gender wage gap among unionized workers is smaller but still present.

“Our guess is that’s because of the usual issues that lead to the wage gap,” said Hegewisch. “Women and men don’t work in the same occupations, or women are more likely to work in some occupations and men in others, and the male occupations tend to get better earnings than the female occupations. But what does fall away in unions is the discrimination in equal pay for the same job; basically there’s greater transparency, and also unions look out for that."

Although the gap has narrowed in recent years, men are still slightly likelier than women to be unionized; recent data from the Bureau of Labor Statistics finds that 12.8 percent of men are represented by unions, compared to 11.7 percent of women.

Yet in several parts of the country with relatively high unionization rates — including the District of Columbia, New York, and every New England state except for Maine — IWPR found that women make up more than half of the unionized workforce.