Claire Cain Miller - NYT News Service

An economic mystery of the last few decades has been why more women aren’t working. A new paper offers one answer: Most plan to, but are increasingly caught off guard by the time and effort it takes to raise children.

The share of women in the United States labor force has leveled off since the 1990s, after steadily climbing for half a century. Today, the share of women age 25 to 54 who work is about the same as it was in 1995, even though in the intervening decades, women have been earning more college degrees than men, entering jobs previously closed to them and delaying marriage and childbirth.

The new analysis suggests something else also began happening during the 1990s: Motherhood became more demanding. Parents now spend more time and money on child care. They feel more pressure to breast-feed, to do enriching activities with their children and to provide close supervision.

A result is that women underestimate the costs of motherhood. The mismatch is biggest for those with college degrees, who invest in an education and expect to maintain a career, wrote the authors, Ilyana Kuziemko and Jenny Shen of Princeton, Jessica Pan of the National University of Singapore and Ebonya Washington of Yale.

The study — a working paper, meaning it has not yet been published in a peer-reviewed journal — tries to quantify what many parents feel as they struggle with the stress of long, inflexible work hours combined with the demands of STEM classes, screen time rules, college prep, family dinners and children’s sick days.

The researchers documented a sharp decline in employment for women after their first children were born, in both the United States and Britain, even though about 90 percent of women worked before having children. They used data from the Labor Department’s National Longitudinal Surveys, the University of Michigan’s Panel Study of Income Dynamics and the British Household Panel Survey. Each covers several decades, but the study focused mostly on women born between 1965 and 1975, who were in their 30s in the 2000s.

For many women, the researchers show, stopping work was unplanned. Since about 1985, no more than 2 percent of female high school seniors said they planned to be “homemakers” at age 30, even though most planned to be mothers. The surveys also found no decline in overall job satisfaction post-baby. Yet consistently, between 15 percent and 18 percent of women have stayed home.

One key to understanding why women have diverged from their plans, the economists found, is that their beliefs about gender roles change after their first baby. The surveys ask questions like whether work inhibits a woman’s ability to be a good mother and whether both parents should contribute financially to a family. Women tend to give more traditional answers after becoming mothers.

The people most surprised by the demands of motherhood were those the researchers least expected: women with college degrees, or those who had babies later, those who had working mothers and those who had assumed they would have careers. Even though highly educated mothers were less likely to quit working than less educated mothers, they were more likely to express anti-work beliefs, and to say that being a parent was harder than they expected.

Though the study did not analyze fathers’ role in depth, it found that their beliefs did not change significantly before and after having a baby. They were less likely than women to say that parenthood was harder than they expected. (Women still do the bulk of child care, even in two-earner families.)

Women got it so wrong, the researchers argue, because it has become harder to work and have children.

The cost of motherhood fell for most of the 20th century because of inventions like dishwashers, formula and the birth control pill. But that’s no longer the case, according to data cited in the paper. The cost of child care has increased by 65 percent since the early 1980s. Eighty percent of women breast-feed, up from about half. The number of hours that parents spend on child care has risen, especially for college-educated parents, for whom it has doubled.

Overall, women have had great success in entering the labor force. Seventy percent of mothers with children under 18 work. Women are more likely to work than previous generations at almost every age, found Claudia Goldin, a Harvard economist. They’re slightly more likely to stop in their late 30s and early 40s, around the time many are taking care of young children — but they usually return to the labor force, particularly if they have degrees.

Still, the new paper raises questions about why the work-family juggle seems to be getting harder. “It is deeply puzzling that at a moment when women are more prepared than ever for long careers in the labor market, norms would change in a manner that encourages them to spend more time at home,” the researchers wrote.

One possible reason is that increasingly, people who work long, inflexible hours are paid disproportionately more, Goldin’s research has found. More women with degrees and these kinds of demanding jobs are having children, and they’re likely to be married to men with similar jobs, as Marianne Bertrand, an economist at the University of Chicago, has described. A result is that dual-earning couples may feel the best choice is for one member, usually the mother, to step back from work so the other parent can maximize the family’s earnings.

To try to set their children on the best path amid increased competition for college admission, parents, especially college-educated ones, invest significantly more time than they used to in child care, found Valerie Ramey and Garey Ramey, economists at the University of California, San Diego. They described it as the “rug rat race” for top colleges.

The lack of family-friendly policies in the United States — such as paid family leave and subsidized child care — most likely plays a role, too. Although policies have improved somewhat since the early 1990s, women’s labor force participation in countries that have more generous policies has continued to increase, unlike in the United States.

As women do more paid work, men have not increased their child care and housekeeping tasks to the same extent — another surprise for young women who, research has shown, expected more egalitarian partnerships.

Generations of girls have been told they can achieve anything they aspire to, including having both a career and children — and many women have done so. But at the same time, both work and parenting have become more demanding. The result is that women’s expectations seem to be outpacing the realities of public policy, workplace culture and family life.

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