An excerpt:

Study coauthor Cassidy Sugimoto, an information scientist at the Georgia Institute of Technology, attributes the results in part to the fact that men are more likely to be principal investigators and thus can make unilateral authorship decisions, which may lead to women’s work being devalued. “What we see is women want to have more clear-cut guidelines,” Sugimoto says. “I think that’s because it protects them, and it gives them tools to use in conversations” with the PI.