Researchers at the World Economic Forum are highlighting a troubling trend: Fewer women around the world are working.

WEF said in a report published Monday that women are slowly narrowing the gender gap when it comes to income and representation in senior management. But after years of closing the gap in workforce participation, momentum has stalled.

The group described the finding as a “worrisome development,” and put forward a handful of factors that help explain the lack of progress.

Automation is having a disproportionate impact on roles traditionally performed by women, WEF said in its annual report on gender. At the same time, fewer women work in growth industries that require skills in science, technology, engineering and mathematics.

Research done in partnership with LinkedIn shows that only 22% of global professionals working on artificial intelligence are women, for example.

“In an era when human skills are increasingly important and complementary to technology, the world cannot afford to deprive itself of women’s talent in sectors in which talent is already scarce,” said WEF founder Klaus Schwab.

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WEF said another potential explanation for weaker labor force participation by women is a shortage of services that would help them enter or return to the workplace, such as daily care for children and the elderly.

The report suggests women are making gains in some areas.

The share of women in managerial positions in both private and public sectors around the world has risen slightly to 33%. The income gap between men and women has narrowed, but it remains at nearly 51%.

At the current pace, WEF estimates it will take 202 years to close the gap women face in the workplace. That figure is based on disparities in earnings, workforce participation and the number of women in top jobs.

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