The penalty persists even after statistically controlling for education, work experience, race, whether an individual works full- or part-time, and a broad range of other human capital and occupational variables. The motherhood wage penalty is not limited to the United States, but has been documented in at least a dozen other industrialized nations. The penalty also has not shown signs of decline over time.
This residual wage penalty may be due to actual productivity differences if responsibility for children leaves mothers with less energy to exert at work. Alternatively, mothers may be paid less than non-mothers because employers perceive mothers to be less productive or have a "taste‟ for discriminating against them.
Career gaps are the most significant contributing factors to what has become known as the motherhood penalty. The coincidence of motherhood and gaps in employment is far from unexpected. Yet, these gaps depreciate earning potential and impede career goal attainment. Even a short hiatus will result in an average wage penalty of 18 percent.
The expectations associated with the ideal employee and the ideal parent are linked to a time when the workforce was comprised mostly of men, and women were largely confined to household duties and childcare. It is due to the social endorsement of these outdated roles that the female parent endures the greatest pressure from family obligations even while engaged in full-time employment. The pervasiveness of stereotypical sex role expectations is a primary cause of the challenges faced by mothers seeking to reenter the workplace.
Thus, the much-reported motherhood wage gap appears to originate, at least in part, from a negative compensating wage differential arising from a relative preference on the part of mothers for an important component of non-wage compensation, namely, health insurance coverage. This finding prevails despite mothers’ overall reduced likelihood of receiving offers of employer health insurance coverage. This conclusion has relevance for the policy discussion concerning the motherhood wage gap, as it suggests a different source of this wage differential and reinforces the importance of job sector choice in driving that gap.
This penalty remains robust to controls for labor supply factors such as education and hours worked per week. Thus, employers pay equally qualified mothers less than they pay childless women in seven out of the eight countries simply because they have a child under six in the home. In addition, all countries show evidence of a fatherhood bonus in pay, although the bonus is not significant in the Netherlands or Luxembourg.
What the findings do indicate, she said, is that "cultural ideas of motherhood are seen as pretty incompatible with cultural ideas of the workplace. Since fatherhood is not seen as incompatible with the workplace, employers do not hold fathers to a harsher performance standard. "The results support the idea that mothers, but not fathers, are discriminated against in workplace-type evaluations," she said.
Mothers looking for employment face disadvantages, including being less likely to be hired, being offered lower salaries and facing a perception that they would be less committed to a job than fathers or women without children, according to an experiment conducted by researchers at Cornell University. "What got me interested in this topic to begin with was research done mostly by economists that showed women with children earned lower wages than women without children, even though they had similar jobs and similar backgrounds," said Shelley J. Correll, associate professor of sociology at Cornell. "This research shows that you earn less if you have one child, even less if you have two, and so on."
When women become mothers, their labor market prospects tend to suffer. A number of studies have documented that mothers experience worse labor market outcomes than women without children.1 Perhaps most well established is the motherhood wage penalty: mothers earn approximately 5% less per child than other workers, over and above any gender wage penalty.
When comparing men and women with the same personal and professional characteristics, the same academic productivity, and both with children, we see that having children affects women much more negatively: a man with children is 4 times more likely to be promoted to Full Professor than a woman with children.