In Forbes, Tim Worstall pinpoints exactly when many women stop earning as much (or more) than their male co-workers:
Currently, among women under 30 or so (it varies, the age, depending upon the average age of first childbirth and this is itself something that varies quite a bit in the US) women tend to outearn men. And as above those without children have, depending upon how you correct for other factors, a positive wage gap in favour of women of about the same size or no pay gap of any relevant size. But there is a pay gap between men and women who have married and who have children (the two effects are not being separated from each other). So, why?
The obvious answer being that this is what humans do. No, it’s no longer true that this is what humans must do, women taking the majority of the child care duties, men going out to work to support everyone. But it is still what the majority do do, it’s the general expectation about how life is going to be worked out. And this does have its effect:
The division of labor in the family is less delineated than it once was and a majority of women with children now work in the market. Nonetheless, women on average still assume greater responsibility for child rearing than men, and that responsibility is associated with a lower extent and continuity of market work. In addition, the expectation and assumption of home responsibilities influence choice of occupation and preferences for working conditions that facilitate a dual career, combining work at home and work in the market. A significant literature has investigated the effect of work in the home on women’s lifetime patterns of labor force participation and the effect of labor force discontinuities on wages.15 Women with children devote relatively more of their energy to home responsibilities than women without children and as a result earn lower wages. On the other hand, married men earn higher wages than other men. Although that effect may be partly endogenous—women may shun low earners as husbands—it is a plausible consequence of the division of labor in the home, which leads men to take greater responsibility for providing the family’s money income and consequently to work longer, more continuously and possibly harder.
In a nutshell, the gender pay gap is really the effect upon the overall averages of two effects. Mothers earn less than non-mothers, fathers earn more than non-fathers. And yes, mothers and fathers are a majority and so the effect is large enough to sway that national average. And while the effect is not entirely symmetric it is reasonably so. We talk of the overall gender pay gap as being around 20% or so, and we see that fathers outearn non-fathers by 8%: that’s a significant portion of that gap right there.
Our conclusion thus has to be that the gender pay gap that we’re seeing isn’t a result of societal discrimination against women (nor of such discrimination in favor of fathers, something that no one at all is complaining it is) but instead a result of the choices that people make about how the kids are going to be cared for and who does it.
