Women in science are less likely than their male counterparts to receive authorship credit for their work, a study shows.

Researchers used a large set of administrative data from universities that revealed exactly who was involved with and paid on various research projects.

They linked the data to authorship information on patents and articles published in scientific journals to see which people who worked on individual projects received credit in the patents and journals and who did not.

The results, published in the journal Nature, show that women who worked on a research project were 13% less likely to be named as authors in related scientific articles compared to their male colleagues.

“There is a clear gap between the rate at which women and men are named as coauthors on publications,” says Julia Lane, a coauthor of the study and a professor at New York University. “The gap is strong, persistent, and independent of the research field.”

And there was another, even larger, gap.

Women are not nearly as likely as men to be named on patents related to projects that they both worked on. Even controlling for all factors, the gap was 59%.

The administrative data that were key to this study came from the UMETRICS dataset available through the Institute for Research on Innovation and Science, which contains detailed information on sponsored research projects for 52 colleges and universities from 2013 to 2016.

It included information on 128,859 people who worked on 9,778 research teams, including faculty members, graduate students, postdoctoral researchers, research staff, and undergraduates.

“We have known for a long time that women publish and patent at a lower rate than men,” says Lane, a professor at NYU Wagner and the NYU Center for Urban Science and Progress. “But because previous data never showed who participated in research, no one knew why. There were anecdotes—like that of Rosalind Franklin, who was denied authorship in a famous Nature article by James Watson and Francis Crick despite correctly demonstrating the double helix structure of DNA—but there was no evidence.”

This study shows that at every position level, women were less likely than men to get credit. The gap was particularly evident at earlier stages of their careers. For example, only 15 out of 100 female graduate students were ever named as an author on a document, compared with 21 out of 100 male graduate students.

Read the full article about women in science by Robert Polner at Futurity.