It's all about mutual expectations - the employers' and women's expectations of themselves, then leading to self-fulfilling realities.

It goes like this. Gross generalizations (which may or may not be true for various cultures, mostly applicable to America as I know it, and also showing the "worst case" scenario, while there are also plenty of "best cases" where we get CEO's, scientists, senators, etc.)

1) As children, girls play with dolls rather than Legos or constructions sets, which impairs the development of their spacial-visual abilities, critical for abstract math and engineering.

2) Most significant - lack of pressure. A boy grows up knowing that one day he will have to provide for an entire family. A girl does not have those expectations. Consequently:

3) Selecting college majors based on what's interesting, and not will enable her to make a good living to support a family. Frequently choosing "soft" subjects such as sociology, psychology, journalism, etc. And if she encounters a particularly difficult college course, what will be her motivation to stick to it? One must have an ambition, a goal. She might have a dream: I want to be a doctor/rocket scientist. But the general, baseline ambition that's based on a sense of obligation and responsiblity, socially instilled, which I believe is pervasive in men (generalizing here, plenty of bums among guys), is missing.

4) Starting a career with an end in mind - "this is only something I will do until I get married and have children." Looking for flexibility over potential growth. Not being committed enough to it. Not being ambitious enough. Does she ever say to herself, "I need to be making 6 figures by the time I'm 30. Will this job get me there? What do I have to do?"

5) So once a woman is in a low-paying job (with an unspoken expectation - either by her or her employer that she will quit when family takes priority), and she has children, she and her husband have to make a decision: who will be the primary breadwinner and who will either not work or compromise their work (take sick days, leave early, etc.) in order to take care of children. And in a vicious cycle, the person with the lower-paying job makes these concessions.

Or worse, they do math where they say: the guy makes 50k, the woman makes 30k, childcare costs 24k. 30-24=6, the woman might as well stay home. Why does the childcare come out of the woman's salary automatically? It should be: 50+30-24=56k - if both people work, they still have 56k left over after childcare.

6) With that in mind, women look for men who are financially successful. That makes no sense to me.

If you have a iota of ambition, then you should marry a man who makes less money than you, so that when you have children, it's him who has to cut down on work hours and worry about the work-family balance.

Women could push back a lot more than they do.