Betsey Stevenson and Justin Wolfers write

So what drives modern marriage? We believe that the answer lies in a shift from the family as a forum for shared production, to shared consumption…the key today is consumption complementarities — activities that are not only enjoyable, but are more enjoyable when shared with a spouse. We call this new model of sharing our lives “hedonic marriage”.

…Hedonic marriage is different from productive marriage. In a world of specialization, the old adage was that “opposites attract,” and it made sense for husband and wife to have different interests in different spheres of life. Today, it is more important that we share similar values, enjoy similar activities, and find each other intellectually stimulating. Hedonic marriage leads people to be more likely to marry someone of their similar age, educational background, and even occupation. As likes are increasingly marrying likes, it isn’t surprising that we see increasing political pressure to expand marriage to same-sex couples.

…the high divorce rates among those marrying in the 1970s reflected a transition, as many married the right partner for the old specialization model of marriage, only to find that pairing hopelessly inadequate in the modern hedonic marriage.

Read the whole thing. This is a big idea.