In a study of earnings inequality among white women, researchers at the University of Massachusetts Amherst find that having children reduces women's earnings, even among workers with comparable qualifications, experience, work hours and jobs. While women at all income levels suffer negative earnings consequences from having children, the lowest-paid women lose the most from motherhood. This earnings penalty ranges from 15 percent per child among low-wage workers to about 4 percent among the highly paid. The findings are published in the October 2010 issue of the American Sociological Review.
The research was conducted by Michelle J. Budig, a professor of sociology at UMass Amherst and Melissa J. Hodges, a graduate student in sociology at the university. It focuses on the motherhood wage penalty meaning how much less women with more children earn relative to similar women with no children, or with fewer children.
Budig says although there hasn't been a lot of scientific study of the work-family issues involved in this wage gap, ordinary working women deal with it on a daily basis and are acutely aware of it.
Budig and Hodges find low-paid women lose proportionately the most earnings for having children, though almost all earners experience significant motherhood penalties. They also find that different processes create the motherhood penalty at different earnings levels. That mothers work less and may accept lower earnings for more family-friendly jobs partially explains the penalty among low-wage workers. Also, that mothers have less experience due to interruptions for childbearing, explains some of the penalty among the highly paid. But a significant motherhood penalty persists even in estimates that account for these differences, the researchers say.
The authors show that estimates of "average" motherhood penalties obscure the compounded disadvantage low-paid mothers face, as well as differences in the processes that produce the penalty. For example, low-wage workers, who are less likely to have leave benefits, may be more likely to quit their jobs when child care demands escalate, thus losing wages through high job turnover. In contrast, high-paid workers with greater access to employer benefits may be better able to maintain connections to employers during childbearing.
And it's only at the very highest level of incomes for married women that the penalty disappears or even reverts to a benefit, the researchers say.
"Based on our findings, the typical full-time female worker earned $1,100 less per child in 2009. This wage penalty for motherhood increases with each additional child and doesn't go away as kids get older. In fact, the penalty grows in size as children age and is a permanent penalty," Budig says. "The motherhood penalty is strongly linked to the gender pay gap, which hasn't budged in size since the late 1990s. Policies aimed at reducing the motherhood penalty should have significant effects on the overall pay difference between men and women with equivalent qualifications and who work in similar jobs."
Using data from the 1979 to 2004 waves of the National Longitudinal Study of Youth from the Bureau of Labor Statistics at the U.S. Department of Labor, researchers tested whether the size of the motherhood penalty, and the processes creating it, differ among white women who are low, middle, and high earners.
For the study, Budig says their definition of top earning women, the upper 10 percent, encompasses those who earn about $60,000 or more in annual salary.
In order to mitigate the effects of the motherhood penalty, Budig and Hodges recommend several policy changes. These include expansion of the Earned Income Tax Credit for low-income families, along with expanded benefits for child care and early childhood education.
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