In What is the gender pay gap and is it real? The complete guide to how women are paid less than men and why it can’t be explained away, Economic Policy Institute senior economist Elise Gould, research assistant Jessica Schieder, and researcher Kathleen Geier outline the ways in which the gender wage gap is measured and answer questions about why women’s average hourly wages are lower than men’s.

Culling from extensive national and regional surveys of wages, educational attainment, and occupational employment, the authors look at the gender wage gap from various angles.

“The gender wage gap is sizeable no matter how it’s measured,” said Gould. “And despite attempts by some analysts, it can’t be explained away with creative number crunching. The gender wage gap is ingrained in our economy and it cannot be solved by simply asking women to make different choices with regard to their education, occupation, work schedules, or family life.”

The authors of the paper highlight that typical women earn about 83 cents for every dollar men earn on an hourly basis and that progress on closing the gap has stalled. They also note the role that race plays in the wage gap, how unions can help narrow the gap, and the “motherhood penalty”—the ways in which a woman’s wages are dragged down after starting a family. Lastly, the explainer points out that, while the gender wage gap has narrowed in recent years, much of that narrowing is due to declining men’s wages.

“There are no simple explanations for the gender wage gap, nor are there simple solutions,” said Schieder. “However, improving women’s economic security requires a focus on pay equity, raising wages overall, and creating a stronger infrastructure for working families.”

One fact that’s clear from the data is that women can’t educate themselves out of the wage gap. For example, women with advanced degrees still make less per hour than men with a college degree.

While adjusting for occupational differences helps distill the role of discrimination in a narrow sense, it cannot capture how sexism and discrimination affect differences in opportunity. A woman’s choices are often influenced by a variety of societal factors that often steer her into lower-paying occupations and fields.

In addition to the gender pay gap explainer, EPI will also release the Gender Wage Gap Calculator, which shows how much higher wages could be today if they had not been eroded by the gender and inequality gaps, as well as a policy memo on steps we can take to close the gender pay gap.