But how does religion factor into that gap?

Two researchers, Dr. Traci Sitzmann (University of Colorado Denver Business School) and Dr. Elizabeth Campbell (University of Minnesota), have just published a paper in the Academy of Management Journal digging into that question, and they found that the more religious a place is, the greater its gender wage gap.

Just consider nations as a whole: In countries where at least 95% of the people say religion is a daily part of their lives, “women earned 46% as much as men.” But when religion was important to less than 20% of the population, women earned 75% of men’s salaries. (Not great. But definitely better.)

What about U.S. states? Using previously published data, Sitzmann and Campbell knew that the gender wage gap has decreased over the past decade — likely as people in power were pressured to correct the problem. But when the researchers grouped the states from most to least religious, it became clear that the more religious states had worse gaps to begin with. And over time, those states closed their gender wage gaps a lot less than the more secular states.