FIG. 1.Change in women’s overall faculty representation for 111 academic fields between 2011–2020, decomposed into change due to hiring (horizontal axis) and change due to attrition (vertical axis, see supplement S1), showing that hiring increased women’s representation for a large majority (87.4%) of fields, while it decreased women’s representation for five fields. Point size represents the relative size of each field by number of faculty in 2020, and points are colored by STEM (black) or non-STEM (gray).FIG. 2.Gendered faculty attrition has caused a differential loss of women faculty in both STEM and non-STEM fields. (A) Gendered attrition in psychology has caused a loss of − 1.83 pp (p < 0.01) of women’s representation between 2011-2020, relative to a counterfactual model with gender-neutral attrition (see supplement S2 B). In contrast, (B) gendered attrition in Ecology has not caused a statistically significant loss (+1.42 pp, p = 0.24). Relative to their field-specific counterfactual simulations, 16 academic fields and the STEM and non-STEM aggregations exhibit significant losses of women faculty due to gendered attrition (circles on figure; two-sided test for significance relative to the gender-neutral null distribution derived from simulation, α = 0.1). The differences in the remaining 95 fields were not statistically significant (x-marks on figure), but we note that their lack of significance is likely partly attributable to their smaller sample sizes at the field-level compared to the all STEM and all non-STEM aggregations, which exhibited large and significant differences. Error bars for the non-STEM and STEM aggregations contain 95% of stochastic simulations. No bars are included for field-level points to preserve readability.FIG. 3.(A) Observed (dotted line, 2011-2020) and projected (solid lines, 2021-2060) faculty gender diversity for natural sciences over time and (B) projections for 10 academic domains over 40 years under five policy scenarios. Line widths span the middle 95% of simulations and gives the mean change in women’s representation across domains over the 40-year period. See text for scenario explanations. OA = observed attrition, GNA = gender-neutral attrition, IR = increasing representation of women among hires (+0.5% each year), ER = equal representation of women and men among hires.FIG. S1.The change in gender diversity between 2011 and 2020 can be approximately decomposed into parts due to hiring and attrition for each academic field, but there is a leftover residual term. In practice, we find that the residual term tends to be very small, such that the decomposition is nearly ideal. The dotted line represents an ideal decomposition, where the change in women’s representation among faculty due to hiring and attrition perfectly matches the total observed change.FIG. S2.Fraction of women among tenure-track faculty hires over time at U.S. PhD granting institutions. Women’s share of new hires is observed to increase at around 0.91 pp annually (p < 0.001), measured by an ordinary least squares regression fit (shown in purple).FIG. S3.Career age distribution of women (red) and men (blue) tenured and tenure-track faculty across all academic fields. Career age is measured as the number of years since earning a PhD. There are substantially more men faculty with high career ages than women faculty.TABLE S1.Trends in women’s representation among new hires from 2012 to 2020 for 11 academic domains, along with academia overall. We use linear regression to measure the expected change in women’s concentration among new hires each year, and find that women’s representation has been increasing in 6 of the 11 domains over time, at rates ranging from 0.58 pp to 1.30 pp per year. The remaining 5 domains have not exhibited significant linear trends. Overall, the fraction of women among hires has been increasing in academia over time (Fig. S2). These findings are qualitatively replicated using logistic regression, so we present the linear regression results here for enhanced interpretability.TABLE S2:Changes in Women’s Representation through Hiring, Attrition, and Gendered Attrition in Academic Fields (2011-2020).Observed changes in women’s representation resulting from hiring and attrition, expressed in percentage points (pp), based on data from Fig. 1, and the estimated average change in women’s representation due to gendered attrition as depicted in Figure 2, accompanied by the 2.5 percentile and 97.5 percentiles of simulations in parentheses. The analysis covers 111 academic fields.