The NY Times has published a nice piece about the rise of power couples and their implications for household inequality. Intuitively, if two top economists who have a stay at home spouse choose to divorce and marry each other then household income inequality increases.  Now, If I may boast for a moment; Dora Costa and I wrote a big paper on power couples back in 2000.

The Times piece implicitly alludes to Gary Becker's work on the economics of marriage.  

Here is a direct quote that I'd like to talk about:

"The nature of marriage itself is changing. It used to be about the division of labor: Men sought homemakers, and women sought breadwinners. But as women’s roles changed, marriage became more about companionship, according to research by two University of Michigan economists, Betsey Stevenson and Justin Wolfers (who also contributes to The Upshot). Now, people marry others they enjoy spending time with, and that tends to be people like themselves.

“Husbands and wives had different roles in different spheres, so that was the opposites-attract view of marriage,” Mr. Wolfers said. “Today you want people with shared passions, similar interests to you, similar career goals, similar goals for the kids.”"

I slightly disagree with this quote.  For decades, economists have been interested in the "make versus buy" decision. If you want coffee, do you go to Starbucks to buy it or do you make it yourself?

When Gary Becker first started writing about the economics of marriage, he was thinking about "household production".  In his setup, households are "firms" that produce quality children and a happy, comfortable household.  In a "closed economy",  spouses must produce all of these goods and inputs to produce the output of quality children and a happy, comfortable home. If the family wants hot oatmeal, one of the family members must make it after buying the oats. Recognizing this fact, spouses faced a time allocation decision concerning who worked and who stayed home and provided his/her time to provide key services.  Comparative advantage led to predictions of the husband working and the spouse staying at home.

In recent decades, more and more educated couples are living in cities.  By the definition of cities, cities feature more markets and the opportunity to go out for dinner, hire a nanny, to pay a dry cleaner to wash your clothes, to pay someone to come over to clean up your house. So, note the "make versus buy" decision. In this Uber age, you can now easily subcontract through the market to provide these "households services".  This change in market structure means that households are more likely to sort on preferences because the efficiency gains within the household are no longer needed as the market can now provide these services.

So, I like Dr. Wolfer's quote but he implies that "preferences have changed" over time.  As a Gary Becker student, I would explain the facts by arguing that market structure has changed.  Almost all household services can now be subcontracted out and this has affected who marries whom.