An explanation for the gender gap doesn't just boil down to rampant sexism. It's a far more nuanced combination of economic, social and educational factors. For instance, the gender gaps between black and Hispanic workers are the narrowest in the United States. Yet, these minority groups receive the smallest median weekly income [source: BLS]. Also, among all full-time workers, the gender gap widens as the pay scale increases. Only in the bottom 25 percent of incomes do women outnumber men.
These inconsistencies begin at the industrial level. Occupational gender distribution is strongly correlated to women's wages [source: Boraas and Rodgers III]. In other words, fields that attract the most women tend to pay less. Education and healthcare industries attract about a third of female employees; the median weekly income of those sectors is $841 and $920, respectively. Roughly the same proportion of men works in computer and engineering fields, where the median weekly salary tops $1,120 [source: BLS]. Even within female-dominated sectors, men still make more money, comparatively. In 1999, a woman working in a majority female workplace earned 25.9 percent less than a woman working in a male-driven sector; a man in the same employment scenario earned only 12.5 percent less [source: Boraas and Rodgers III].
Women's heavy participation in particular fields also implies an underlying social dynamic. While the feminist movement has made significant strides in erasing gender stereotypes in the workplace, some people still perceive certain jobs as better suited for women than men. Science-related fields, which contain disproportionately high numbers of men, have strived to close their gender gaps in recent years. Such efforts appear to be taking effect, with women earning 40 percent of science and engineering Ph.D.s in 2006 [source: Angier].
At the end of the day, the people bringing home the most money are usually the ones who put in the most time. Employees who work 45 hours per week, as opposed to 40 hours, earn 44 percent more on average [source: Tischler]. The pay scale difference from working overtime could also contribute to the gender gap. According to the BLS, men in 2007 labored on the job at least 41 hours per week, while the same held for 15 percent of full-time female workers [source: BLS].
But do women spend less time on the clock due to childcare responsibilities?