  Female researchers may have experienced more difficulties than their male
counterparts since the COVID-19 outbreak because of gendered housework and
childcare. Using Microsoft Academic Graph data from 2016 to 2020, this study
examined how the proportion of female authors in academic journals on a global
scale changed in 2020 (net of recent yearly trends). We observed a decrease in
research productivity for female researchers in 2020, mostly as first authors,
followed by last author position. Female researchers were not necessarily
excluded from but were marginalised in research. We also identified various
factors that amplified the gender gap by dividing the authors' backgrounds into
individual, organisational and national characteristics. Female researchers
were more vulnerable when they were in their mid-career, affiliated to the
least influential organisations, and more importantly from less gender-equal
countries with higher mortality and restricted mobility as a result of
COVID-19.
