The proportion of women getting PhDs in science, technology, engineering and maths (STEM) in the United States has remained stagnant in the past decade, despite a 50% increase in the number of STEM doctorates awarded in the same period. The figures, released last month by the National Student Clearinghouse Research Center in Herndon, Virginia, in its report Snapshot 27: Science and Engineering Degree Completion by Gender, showed that although the number of STEM PhDs rose from about 18,000 in 2006 to more than 27,000 in 2016, the proportion of doctorates awarded to women remained at around 40%.

“So much attention has been paid to making hard-science disciplines more inviting to women, and a lot of institutions can claim progress,” says Douglas Shapiro, the centre's executive research director. “But when you look at the big picture, you don't see it.”

The report offers the first national-level snapshot of science and engineering degrees awarded in 2015–16, which the centre compared with those earned in 2006. It breaks STEM degrees into seven fields: engineering; computer science; Earth/atmospheric/ocean sciences; physical sciences; maths; biological and agricultural sciences; and social sciences and psychology.

The proportion of PhD degrees earned by women increased by no more than a few percentage points over the decade — except in maths, where it fell slightly from 29.2% to 28.4%, and in social sciences and psychology, where it fell from 56% to 55%.

The share of bachelor's degrees earned by women also fell during the decade in four disciplines: in maths (from 44.6% to 42.3%), in computer science (from 20.2% to 18.6%), in Earth sciences (from 40.3% to 38.2%) and in physical sciences (from 41.8% to 38.8%). Fewer bachelors degrees translates into fewer advanced degrees later on. “It's disheartening,” says Shapiro.

Since 2009, the only field in which women studying STEM subjects have earned a higher proportion of doctoral degrees is biological and agricultural sciences, according to the report. In 2006 they received 47.9% of PhD degrees in the discipline but that shifted to 51.6% by 2009. The trend continued through to 2016 when women earned 51.8% of PhDs in biological and agricultural sciences.

Shapiro says that the imbalance reflects the need for closer tracking of degree-earners.