It’s not baby-sitting when Daddy does it.

Oh U.S. Census Bureau, you silly sometimes:

When both parents are present in the household, the Census Bureau assumes for the purposes of its “Who’s Minding the Kids?” report, that the mother is the “designated parent.” And when the designated parent is working or at school, the bureau would like to know who’s providing child care.

If the answer is Daddy, as it was 26 percent of the time when these numbers were last released, in 2005, and 32 percent of the time in 2010, the Census Bureau calls that “care.” But if Mom is caring for a child while Dad’s at work, that’s not a “child care arrangement,” but something else. Parenting, presumably.

“Regardless of how much families have changed over the last 50 years women are still primarily responsible for work in the home,” said Lynda Laughlin of the Census Bureau’s Fertility and Family Statistics Branch. “We try to look at child care as more of a form of work support.” A mother, said Ms. Laughlin, is “not only caring for the child only while Dad works. She’s probably caring for the child 24 hours and so Dad is able to go to work regardless.”

That bears repeating. If, every morning, I go off to work and my husband stays home with a child, that’s a “child care arrangement” in the eyes of this governmental institution. If the reverse is true, it’s not. I asked Ms. Laughlin if the Census Bureau collected data on the hours mothers spend offering “work support” to their husbands. “No,” she said. “We don’t report it in that direction.”