Last week, I wrote about the economics profession’s new “power couple”, Justin Wolfers and Betsey Stevenson, and mentioned the idea of shared consumption driving marriage rather than shared production. In the comments, Katina asked me to explain shared consumption a bit more in depth and I promised her a longer post on the matter. I’m a little late, but here it is. I haven’t formally modeled any of this, and so I’ll say it’s not very clearly thought out, but in the name of elucidating the inner workings of this economist’s mind, I figured I’d at least outline my thoughts here.
One of the perhaps more complicated ways to define shared consumption comes from the study of public goods. Public goods are things like national defense or clean air. They constitute things that are non-excludable and non-rivalrous in consumption. There’s a lot of buzz words in that sentence, but just think about things that you can enjoy (or gain utility from) without diminishing someone else’ enjoyment (this is the non-rivalrous part) and things that, once they are in existence, no one can easily prevent someone else from enjoying it, say through an entrance fee (this is the non-excludable part).
Shared consumption goods are a little less strict than this, however. The idea of shared consumption lets us take what we would normally call “private” goods (non-public, like shoes–we both can’t wear the same pair of shoes) and give them some public (or sharing) aspects within a marriage or partnership.
A big shift in family economics has been to examine children as a public good. See, for instance, Chiappori, Iyigun and Weiss. The idea is that two people investing in a child reap benefits from both their own investment and the other’s investment. But this is a little convoluted for a non-economist, maybe.
Perhaps even simpler is when we take children out of the equation. Many couples these days marry without any intention of having children, even if though it might mean paying more in taxes. Two-earner households aren’t specializing in household production by one staying at home to cook and clean while the other works, but rather enter into a marriage for the purpose of keeping each other company.
To back me up, the New York Times published a piece outlining a significant demographic shift in parenthood over the past few years. Namely, more than half of children born to mothers under 30 are born to single mothers. If that’s not a refutation of shared production, I don’t know what is. This is a theme that is also prominent in my new favorite ethnography (not so new, really, but if you ever want to see me get really excited, ask me about Promises I Can Keep).
In addition, I’m currently reading Is Marriage for White People? by Ralph Richard Banks of Stanford Law. Early on, he cites a Pew study that says shared religious beliefs, shared interests, a healthy, happy sexual relationship and even sharing household chores were more important for a happy marriage than children. We’re not getting married to have children, necessarily, anymore, and when we are, we’re not convinced that specializing in raising the child is the best thing for one parent to do.
As pertaining to children, there’s a fine line between what constitutes consumption and production, but I think it’s safe to say that most matches aren’t happening with the primary purpose of building a home with a white picket fence in the suburbs and raising a couple of kids who go on to do the same. Americans are marrying to make themselves better off still, just not in the way that our parents and grandparents did.
ERIN K. FLETCHER 
