In a groundbreaking study of more than two million books published in North America between 2002 and 2012, scholars found that books by women authors are priced 45% less than those of their male counterparts. The researchers, sociologist Dana Beth Weinberg and mathematician Adam Kapelner, both from Queens College-CUNY, say there is a lot more to the story than can be gleaned from this price gap alone.

The paper, published in the journal PLOS One, found that there are three ways that discrimination unfolds. First, female authors are published less than male authors in particular genres. Second, genres that are thought of as traditionally women-oriented–like romance–are assigned less value by the industry. And finally, there are gender differences in the prices of books within the same genre. But even accounting for all of these differences, publishers paid authors with identifiably female names 9% less than authors with male names.

The scholars also considered whether gender inequities play out differently in traditional publishing as opposed to independent publishing, such as self-publishing your book on Amazon. In a fascinating twist, they found that indie authors generally replicate the same patterns of gender discrimination in traditional publishing, but there is more equality over all.

The similar pattern might be attributed to the fact that consumers are conditioned to pay less for books by women or within traditionally female genres. But because indie writers are able to set their own book prices, there was more parity in the price of books. So while indie titles are priced lower–on average–than traditionally published books, there was only a 7% price gap overall, compared to the 45% gap in traditional publishing.