The idea of "assortative mating" is covered in depth in http://www.amazon.com/Marriage-Markets-Inequality-Remaking-American/dp/0199916586 http://www.amazon.com/

The idea of "assortative mating" is covered in depth in http://www.amazon.com/Marriage-Markets-Inequality-Remaking-American/dp/0199916586 http://www.amazon.com/Marriage-Markets-Inequality-Remaking-A... I have no affiliation with the book, I just read it recently and thought someone might be interested in the topic.