On average, in the United States, women are paid 79 cents for every dollar their male counterparts make. That’s called the gender wage gap.

Sarah Kliff, the deputy managing editor for visuals at Vox, breaks down why that 21 cents is a lot more complicated than it seems, and what we could do about it in her piece, “The Truth About the Gender Wage Gap.”

Click the audio player above to hear our interview with her.