I won't dispute that there is some level of extra assortive mating going on because of more equal opportunities for women. Even if it was just due to more opportunity and exposure, that makes sense. I do question whether in the past if the physician that married the nurse was really providing any sort of opportunity for status change (in either economic or social standing) in most cases, since I imagine the nurse and physician probably came from similar social standings, and thus likely similar economic standings.

If the nurse or secretary of 20 or more years ago was "from a good family", what change was really spurred by the union?