In the past year, the persistent wage gap between male and female earners has become a topic of national conversation. Prominent actors including Patricia Arquette, Jennifer Lawrence and Bradley Cooper have openly criticized Hollywood for underpaying its female stars. On the presidential campaign trail, candidates from both parties have been asked where they stand on the issue. And numerous bills are being debated in state capitals from coast to coast.

Although pay discrimination has been illegal for decades, women still earn just 79 percent of what men make on average. While the gap narrowed considerably between the 1970s and the 1990s, progress has stagnated, hovering between 76 percent and 79 percent since 2001. In addition, women, particularly in lower-paid positions, are less likely to have access to health insurance, retirement benefits and paid leave.