Opinion | The Gender Pay Gap Is a Culture Problem

In my mind, one limitation in interpreting these findings is that I.V.F. pregnancies are planned, while over 40 percent of pregnancies in the United States, for example, are unplanned. One could imagine that the women pursuing I.V.F. at various income levels might be better set up to weather a career interruption than women who have surprise pregnancies. But it is still a thought-provoking finding that complicates previous child gap research.

In the United States, where gender norms are less progressive than in Scandinavia and the “costs for a single cycle of I.V.F. have recently been estimated to range from $15,000 to $20,000 and can exceed $30,000,” according to the Department of Health and Human Services, we find a very different experience with the motherhood pay gap than in Denmark. And it’s a much less happy picture.

A paper published last year in the scientific journal PNAS looked at 22 years of administrative data from the United States and found “surprisingly robust” motherhood penalties, even, unfortunately, in circumstances in which you might expect that the penalty would be slim, like in female-breadwinner families:

On average, women earn 57 percent more than men in these female-breadwinner families. Were couples simply seeking to maximize household income conditional on a certain amount of time investment in children, we would expect to see fatherhood penalties. Instead, we see one of the largest motherhood penalties in female-breadwinner families. Indeed, higher-earning women experience a 60 percent drop from prechildbirth earnings relative to their lower-earning male partner and the highest of our various sample stratifications. The pattern we find for the United States is the polar opposite of that for Sweden.

There was also no difference for mothers in companies that were female led or had a majority of female employees. “If anything,” according to the authors, “this motherhood penalty grows faster over time at firms headed by women. On the whole, our findings are discouraging even relative to the existing work on motherhood penalties.”

I asked one of the paper’s co-authors, Cecilia Machado, an economist at the Getulio Vargas Foundation, to summarize the state of the motherhood penalty in the United States. If we wanted to take steps to improve the pay gap as a society, what would we do? Via email, she said that there might be a limited scope of what public policy and workplace policy can do. But she added that federal and workplace policy that encouraged both men and women to take paid parental leave could help; creating the political conditions for involved fatherhood in a child’s first year can set egalitarian patterns that last a lifetime. Still, Machado said, “Both of these combined are important policies, but maybe them alone, by themselves, will not work if we don’t see culture and gender norms changing.”

My take is that we’re in a time when cultural norms around motherhood in the United States seem particularly contradictory and in flux. While a record high percentage of women with children under 5 work, a large subset of Americans still thinks society would be better off if they didn’t.