Ledbetter’s case shows how pay secrecy can cause the pay gap between men and women, a gap that widens between men and women of color. More than 50 years after the Equal Pay Act, study after study show that women are still paid less than men for the same work. Some have argued that the pay gap is effectively a myth, attributing it to women’s career choices rather than workplace discrimination. If only that were true. As the National Women’s Law Center has repeatedly pointed out , this “ignores the fact that ‘women’s’ jobs often pay less precisely because women do them, because women’s work is devalued, and that women are paid less even when they work in the same occupations as men.” Even when you look at industries dominated by one sex or the other, the pay gap exists in both .

Ariane Hegewisch is the study director at the Institute for Women’s Policy Research and the author of several reports on pay secrecy and wage discrimination. One of the reasons she sees behind the pay gap is that, five decades after the Civil Rights Act outlawed discrimination on the basis of sex, old-fashioned workplace beliefs still justify sexist pay distribution. For example, in one case, in which a group of women sued Walmart for sexist discrimination in pay and promotions, women testified that their managers said men “are working as the heads of their households, while women are just working for the sake of working,” even though women are now the sole or primary breadwinners in around 40 percent of American households.