I would disagree a bit on the second phase; women typically initiate divorce. But I think you have the phases right. Something else to consider is that men have and will likely continue to come out the winner in all this. Feminism is a curse for women.
I found an old Fortune Magazine article on trophy wives that illustrates the trend I am talking about, but there are no statistics in it.
http://fortune.com/2015/12/24/the-ceos-second-wife-fortune-1989/
It does, however, give the distinct impression that as of the 80s, this was a male trend. And of course, upper-class white women have always driven the feminist agenda as far as I can tell. So the "dumped for a younger woman" narrative that drove 2nd wave feminism may not have accounted for the majority of divorces, but it could easily accounted for the majority of the voices that were heard.
Oh, as for men being the winners... maybe? I think they have the advantage until they either get married or impregnate some woman, and then the tables flip with lightning speed. For myself, it’s not about winning or losing. It’s just about being able to live alone and free, and pay my own way, and... just be free. I can’t put it any other way: I do not like being a wife or a girlfriend or a lover or any of it. A hundred years ago, I’d have had little choice unless I had a father who supported me, maybe had a business and helped me out, or put me through school. But my own father was a deadbeat with criminal tendencies, my mother’s family was poor, I was on my own. So yes, without laws that enabled me to join the military, work my way through school, get credit, get a place of my own, etc... I’d have had a lot fewer opportunities.
bump