The core basis for the wage gap is not number of hours of overtime worked, or time on the job, or risk or unpleasantness involved in the job etc. --- those are outward signs of the real deal, that there are different expectations on men and women in society. Like, really.
Most women look to earning power in a man as an important feature. Not all, most. Most men may think about it in terms of a woman, but then get distracted when she arches her chest out while taking off her jacket.
I was hypnotized by the "equality" thing in college, but when I got out in the real world, I had to rethink my calculations a bit, after seeing women in their early 20s (my age at that time) working as secretaries without a college degree who were already modestly bragging about the size of their house, their trip to Italy and their new car. This wasn't paid for out of their secretary's salary. It wasn't going quite as well financially for me, although I ostensibly earned more money as a college grad. It dawned on me that one day, if I worked hard, I too could then afford to support one of these women - and would then be in the position of her husband. LOL
Some women are really into the work they do, they want to do the best job they can, and they want to keep moving forward - and also be honest about the money. And then there are other women. You can sort out the percentages based on your own real-life experience.
But if you look at it that way, OF COURSE some women who have husbands supplying the real breadwinning are not going to be as motivated to move up. They don't care. Frankly, if I won the lotto, I wouldn't care either. Although I actually like my job now (I didn't when I was in my 20s), I think there's a difference between the word "hobby" and the word "job". "Job" means that you have to do it, even on days you don't feel like it. "Hobby" means that you do it when you want, or you try out something you want, or you do it until you don't want to do it anymore, while something or someone else regularly pays for things.
Some men (like ... me) have the experience of finding the work world to be a bit dull out of college, to put it mildly, but after you find a niche and get competent at something, it's not so bad, in fact work is sometimes even fun and a source of pride ... like a hobby. But you have to go through the apprenticeship of having all the crap jobs thrown your way as a newcomer when you are young. For a lot of young women, there is an alternative way out: through a man. So they never get into that mode; they take the easy way out. Maybe it's better that men have to struggle upwards and women CAN struggle upwards, but for many it's just too easy to "retire" at a young age.
