By top 10%, I mean the top 10% of intellectually gifted women who were being artificially held back from producing large economic value in society.
I therefore introduce the concept of assortative mating.
Assortative mating is the process by which people of similar backgrounds, such as educational attainment or financial means, select a partner. Over the past half-century, there has been an increase in positive assortative mating within the marriage market.
In the past many of these women, denied opportunity, were forced to hitch their wagon to a man for success, and used their intellectual capacity to help advance his career (leading to the old saying: 'behind every great man is a great woman'). But in more recent generations, we've seen a dramatic increase in assortative mating at the top end, which has resulted in more high IQ men and women pairing up and combining their economic capacities.
The obvious result of this is doubly beneficial to the top women in particular, because not only are they earning dramatically more than the median, but they're doubling up (or more) by matching with a equal or higher earning male. It's not hard to imagine why this phenomena is exacerbating income inequality, as these relatively new 'super couples' (often choosing not to pursue having children at all or only limiting it to 1 after building a career) grow their wealth early and dramatically, buying up valuable assets like housing that average or median couples need (but increasingly can't afford) to build a family, and passing it on to fewer kids once they die.
These couples are in essence gaming the system as the birthrate continues to fall and normal women are left wondering 'where all the good men are' and why life seems so hard. While men do have a general willingness to 'date down' that inherently reduces inequality that is obviously not a static tendency, and the prospect of doubling a high income is still economically enticing. How much women make and how smart they are does matter to the top producing men of society, it's just that it matters less than women think it does from their perspective.
It is for this reason, I believe it would be wise for society to economically tax these couples to a larger degree than would otherwise be the case if they had 3 or more children, because they're disproportionately driving up the cost of living through asset price inflation. It's not all about the billionaires reaping untaxed capital gains (though that's certainly a concern too).
This money should be allocated to subsidize home loans for the bottom 80-90% of society on a sliding scale designed to facilitate family formation and higher birth rates. Owning multiple properties under 5000 square feet should be regulated as well, to further disincentive rich childless couples from buying up all the necessary assets for life.
I believe this phenomena explains the paradox of declining female happiness better than most. Most women just want a normal life, they aren't super-women that want to compete against other top men, but increasingly they are denied this for largely economic reasons. The other side of the equation is that since female empowerment in the labor market, median male wages have remained stagnant despite rising productivity (reducing the attractiveness of settling). Instead, normal women are now relegated to wage slavery out of necessity that's arguably not beneficial to their long term happiness.