A lot of the gap between genders can be blamed on the fact that technology has made a lot of jobs physically easier and mentally harder.  Women are still on the average physically weaker, so now a lot more jobs are those in which women can potentially compete with men in a way they could not in the past. Francis Fukuyama, in his excellent work The Great Disruption, says that this change is a major cause of the moral chaos of recent years; as women and men become substitutable for each other in more and more work situations, technology allowing, so women and men are increasingly substitutable for each other in other contexts – including, in some places, as a marriage partner!  Rosie the Riveter, during World War II, was happy to stop riveting and go back to being a housewife.  A lot of women”s jobs aren”t like that now. And where they are, I don”t think that there is a “lump of labor” or a fixed amount of work that needs to be done, so that every woman working necessarily displaces a man, but there is a “lump of land” for housing, so that once there is a critical mass of two income couples, housing prices and rents are bid up and all spouses must now work.  Warren and Tyagi, in their book The Two Income Trap, make clear that at least before 2007 it was not the price and labor value of most consumer goods, but the price of three or four particular things that have meant that spouses “had to” work.  They are housing [both rented and owned], tuition [for those in public school, “tuition” is factored into housing], health care, and income tax bracket creep.  Wages had not fallen behind in relation to most things one buys at the mall.  They have fallen behind in relation to those four things.

Related: “Unraveling the Achievement Gap on Campus” by The Contrarian