Everyone is trying to figure out what went wrong with jobs in April.

It’s way too early to tell for certain why the numbers came in so much lower than expected. But we can start to make some educated guesses based on the data.

One of the possible causes of the severe miss in April’s jobs numbers is likely the fact that nearly half of U.S. school age children still cannot attend school for full-time, in-person instruction.

The evidence for this comes from data about women—on whom childcare burdens tend to fall—in the workforce.

The number of women aged 16 and over who are employed actually shrank by 8,000 in April, following growth of nearly 600,000 in March. The number of adult women, aged 20 and over, working shrank by 83,000. That is not something you would expect in a rapidly growing economy.

The number of married women employed fell by nearly 900,000 in April, while the number of married men rose by 110,000.

The number of men in the work force aged 20 and older grew by 355,000 in April, while the number of women aged 20 and older shrank by 165,000 on a seasonally adjusted basis.

There was a striking racial disparity in the jobs figures for women. The number of adult white women in the labor force shrank by 308,000. The number of adult black women working rose by 134,000.  The adult Hispanic workforce shrank by 119,000.

The percentage of working age women in the workforce also shrank.  And most of the contraction due white women dropping out, with participation fell from 56.6 percent to 56.2 percent and the employment-population ratio falling to 53.5 from 53.7. The participation rate for black women rose to 60.7 and the employment-population ratio jumped higher to 55.5 from 54.8.  Participation for Hispanic women dipped from 58.3 to 57.6 and the employment-population fell to 53.3 from 54 percent.

As ZipRecruiter’s Julia Pollak points out, hybrid schooling—kids attending school a few days a week and remotely the rest of the time—is likely keeping women out of the workforce.

It’s not only school closings, of course. It’s likely some women are holding out for better wages and working condition, something they are enabled to do because of stimulus checks and enhanced unemployment benefits. Others may be awaiting their own vaccination before returning to work.