Christina Hoff Sommers recently wrote about "Equal Pay Day," the day feminists have set aside to moan about the fact that women earn on average 78 percent of men's pay. Among other things, she wrote,
Excuse me for interrupting, but this holiday has no basis in reality. Even feminist economists acknowledge that today's pay disparities are almost entirely the result of women's different life choices -- what they study in school, where they work, and how they balance home and career. This is not to deny that some employers will try to pay Jill 78 cents and Jack $1.00 for an identical job. But our strict laws give Jill the right to take that employer to court. The claim that American women as a group face systemic wage discrimination is groundless.
So, what determines the way in which women's lifestyle choices, including "what they study in school, where they work, and how they balance home and career," differ from those of men. Answer: to a large degree, hardwired sex differences, the product of millions of years of evolution, specifically in the differential effects which reproduction has on men versus women.
As will be known to students of evolutionary psychology, the greater reproductive burden of women as compared to men has made them the choosers when it comes to mating and reproduction. Historically, most societies have been at least somewhat polygynous, with some men having multiple wives, and others having none. According to the psychologist Roy Baumeister, throughout history around 80 percent of women have left descendants, the corresponding figure for men being around 40 percent. As he says, we are "descended from twice as many women as men." Those 40 percent of men who did reproduce will have been those that took greater risks to earn wealth and status.
Men seem hardwired to be risk takers, for without such a trait they may be doomed to celibate status. Of course, in the modern world, risk doesn't take the form of killing saber-toothed tigers nor (usually) protecting home and hearth from armed invaders. Rather, it takes the form of trying to climb the corporate ladder, or earning more money however possible, including taking risky jobs that pay more because of their risks. Men are more prone to aggression and violence, competition and dominance.
Women seem far more interested in a protective environment, are more concerned with social relationships, and more nurturing and empathetic than men.
All of this translates into the modern workplace and is likely mainly responsible for differences in pay between the sexes. Men are on average always more interested in doing whatever it takes to make more money, whether this means long hours away from home, taking risky jobs in coal mines or on oil rigs, or moving to inhospitable environments.
A recent survey of the best-earning college degrees showed that these were highly skewed towards fields in which men dominate, including such things as eight types of engineering, economics, and physics. On the face of it, there seems to be a couple of reasons women do not enter these fields: one is that they are technical, and therefore not conducive to a nurturing or people-oriented mindset, and the other is the sheer amount of work and dedication involved to succeed in these areas, something more likely to be found in someone who wants to achieve at all costs, i.e. a man.
The economist Mark Perry recently wrote about sex differences in workplace fatalities, with men on the receiving end of 92.7 percent (4,703) of deaths in the workplace in 2008. Perry says:
Because male workers are disproportionately exposed to dangerous work conditions, the wages in many male-dominated professions reflect a wage premium to compensate for the higher occupational risk, and this is one reason for a gender wage gap.
This has nothing to do with discrimination, but can be explained by gender differences in workplace risk tolerance. On average, men are more willing than women to accept higher compensation for a higher risk of work-related death or injury.
Women are just far less likely to desire to work in dangerous, premium-paying jobs, or to do whatever is necessary to earn more money, whether it's majoring in a tough field like chemical engineering or working overtime to achieve promotions and raises. Men are the risk takers, and this translates into higher pay. That women earn 78 percent of what men earn is not at all due to discrimination or sexism, and seems generous to boot.