New Insights into the Mommy Track, Part I

Women’s career issues are a frequent topic of this blog, and I have been thinking about them again while putting the finishing touches on a manuscript, Quick Nontraditional Careers Guide: Eight Steps for Defying Traditional Gender Roles, due to be published in June. I also wrote about these issues in the volume about nontraditional careers that is part of Progressive Careers. This week I also learned about two new research studies that cast additional light on this subject, showing that the consequences of the mommy track vary greatly. More highly skilled women, particularly in certain fields, suffer a greater penalty for choosing to have children.

David Ellwood, Elizabeth Ty Wilde, and Lily Batchelder, in “The Mommy Track Divides: The Impact of Childbearing on Wages of Women of Differing Skill Levels” (PDF), wanted to know why childbearing by female college graduates has declined so much. Among those born in the early 1940s, nearly 50% of them had borne children by age 25, and only 18% were childless at age 40. Among the cohort born 20 years later, only 20% had borne children by age 25, and more than 25% remained childless at age 40. By comparison, in both generations, women who were not college graduates bore children earlier in life, with little generational difference in their timing.

The researchers hypothesized that the college grads were postponing childbearing to allow themselves time to establish a career and thus minimize the wage impact of the mommy track.

The researchers used data from a longitudinal study, dividing the women into low-skill and high-skill groups based on their performance on the Armed Forces Qualification Test. (They used that rather than college attendance, because early childbearing clearly can and does influence education.) They then compared the income trajectories of the two groups and found that the low-skill group had a trajectory that not only was flatter (as would be expected) than that of the high-skill group but also less affected by child-bearing. Having children later or not at all improved their earnings only modestly. For the high-skill women, however, the income rise was steeper but leveled off when they bore children, a mommy penalty that persisted even a decade after childbirth. But by postponing childbirth, the high-skill women had achieved a higher pre-child earning level and therefore leveled off at a higher plateau. In other words, for high-skill women it pays to establish a career before having children (if ever). This would explain the historical fertility and timing differences mentioned earlier.

Another interesting question is why women’s earnings suffer after child-bearing. Is it because they shift to part-time work or a less demanding occupation, leave their employer (thus losing human capital), or drop out of the workforce entirely (thus forgoing work experience)? The researchers found that all these behaviors have an impact, but there is additional impact that can’t be explained by these. Even women who stay full-time in the same occupation with the same employer suffer a 14% loss in earnings. Evidently, some other factor, such as discrimination or a perceived loss of career commitment, is depressing earnings.

It’s useful to note what the researchers found about high-skill men’s earnings. Like the high-skill women, those who postponed parenthood had higher earnings, but the arrival of parenthood had a much smaller impact than it had on the women. Most interesting was the finding that men who remained childless had the lowest earnings of all in the high-skill group. There’s a chicken-egg problem here: Does fatherhood make men strive more, or do low-earning men make less attractive partners for starting a family?

Apart from its findings about the wage penalty of the mommy track, this study produces two disturbingly different portraits of child-bearing behavior. One, among low-skill women, consists of child-bearing at a young age, much more often outside of marriage, with low earnings and little prospect of a large increase in earnings later on. The other behavior, among high-skill women, consists of child-bearing by a typically married couple in their peak earning years. You can imagine very different outcomes for the children in these two scenarios.

In next week’s blog I’ll write about a different study that looks at how, among highly educated women, different occupations cause the mommy track to have different impacts.