  There is extensive, yet fragmented, evidence of gender differences in
academia suggesting that women are under-represented in most scientific
disciplines, publish fewer articles throughout a career, and their work
acquires fewer citations. Here, we offer a comprehensive picture of
longitudinal gender discrepancies in performance through a bibliometric
analysis of academic careers by reconstructing the complete publication history
of over 1.5 million gender-identified authors whose publishing career ended
between 1955 and 2010, covering 83 countries and 13 disciplines. We find that,
paradoxically, the increase of participation of women in science over the past
60 years was accompanied by an increase of gender differences in both
productivity and impact. Most surprisingly though, we uncover two gender
invariants, finding that men and women publish at a comparable annual rate and
have equivalent career-wise impact for the same size body of work. Finally, we
demonstrate that differences in dropout rates and career length explain a large
portion of the reported career-wise differences in productivity and impact.
This comprehensive picture of gender inequality in academia can help rephrase
the conversation around the sustainability of women's careers in academia, with
important consequences for institutions and policy makers.
