https://www.sciencedaily.com/releases/2019/04/190401133038.htm

Many explanations have been proposed to explain this so-called leaky pipeline effect including family responsibilities, biological differences and unconscious bias in the workplace.

A team of researchers led by Sara Clifton from the University of Illinois at Urbana-Champaign has developed a new mathematical model to study the ascension of women through professional hierarchies, described in the journal Chaos, from AIP Publishing. The model factors in the relative roles of bias and homophily (the tendency of people to seek others similar to themselves) in various fields. Unlike prior work, their new model predicts that gender parity is not inevitable and deliberate intervention may be required in various fields to achieve gender balance.