At my first job out of college, one of my coworkers told an unforgettable anecdote about a research project he once worked on as a student. At the time he was helping an economist study marriage patterns across the US, and they needed to understand how marriage laws differed by state. So my coworker went to the library, approached the librarian, and had the following exchange:

Research assistant: “Hi. I need to find out the minimum legal age of marriage in each US state. Can you help me?”

Librarian: [Long pause, stares back suspiciously.] “She’s too young for you.”

I bring this up because a) I find this story hilarious, and b) it illustrates that economists have long been curious about how marriage patterns impact economic outcomes. A NY Times blog post from a while back summarized some of the recent research on this, specifically with a focus on income inequality. The way we commonly choose a marriage partner, it turns out, could be playing a significant role in America’s growing income divide.

From the article:

These days, an investment banker may marry another investment banker rather than a high school sweetheart, or a lawyer will marry another lawyer, or a prestigious client, rather than a secretary. Whether measured in terms of income or education, there are more so-called power couples today than in the past, one manifestation of a phenomenon known as assortative mating, or more generally the pairing of like with like…

Money and talent become clustered in high-powered, two-earner families determined to do everything possible to advance the interests of their children…

The numbers show that assortative mating really matters. One study indicated that combined family decisions on assortative mating, divorce and female labor supply accounted for about one-third of the increase in income inequality from 1960 to 2005.

This was a shock to me when I read it. Income inequality in the United States is at its worst in nearly a century. Most people seem aware of this, but how we get married is rarely one of the reasons cited for the trend. Instead, it’s the usual mix of globalization, technology, and union decline that most use to explain the growing chasm between the haves and have-nots. On occasion, smart economists highlight deliberate government actions over the past few decades, like cutting taxes on investment income or relaxing bank regulations, for the explosion of incomes at the top. But social dynamics aren’t usually part of the discussion.

Nonetheless, the finding that marriage can have such significant implications for inequality makes a great deal of sense to me personally. Back when my wife and I were new parents living in a mostly middle class Connecticut city, we had many late night, anxious conversations about the mediocre schools in our town on the one hand and the area’s stratospheric cost of private education on the other. Southern Connecticut, it turns out, is like a souped-up microcosm of America in that regard; public institutions are under fiscal pressure just like everywhere else, relegating the kids of blue collar native-born Americans and first generation immigrants to middling schools, while the area’s bankers, executives and hedge fund managers drive up the cost of living, from houses to school tuition to haircuts. As kids clump together in socially and economically-segregated schools, they’re more likely to interact with and marry those just as privileged as they are, deepening the inequality gap over generations.

What’s the solution to this vicious cycle? First, public policy can make a huge difference by improving the quality of public schools, such that rich, talented parents actually want to send their kids there, and that those kids might mix socially with their less privileged peers. As I understand it, this was a key ingredient in the post-WWII economy, one characterized by stable growth and low inequality; good public education during that time not only produced talent and raised the economy’s productivity, but it also helped maintain a flat society.

But as in many cases, public policy can’t do the job on its own. Solving a social problem as weighty and challenging as this one requires individuals and families to change how they live and interact with others. As I wrote recently on the subject of race, it’s not good enough to have character and integrity in a vacuum. If you want the issue of racism in America to improve, we will have to seek out friends, coworkers, and family members of different races, and consciously include them in our personal lives.

So it is when it comes to class and social status. Given that these days we so commonly live in sequestered little communities where our neighbors have similar incomes and similar education levels, if we actually care about the societal implications of runaway social and economic segregation in America, we can’t just sit there and wait for a solution to descend from heaven. To get out of our comfort zones and to “forcibly agitate” our lives, in the language of that aforementioned blog post, might be the only way to break the cycle.

This takes a radical change in how we live, but on an even more basic level, a major shift in how we view other human beings. Abdul-Baha, for one, asks no less of us than this:

See ye no strangers; rather see all men as friends, for love and unity come hard when ye fix your gaze on otherness. And in this new and wondrous age, the Holy Writings say that we must be at one with every people… they are not strangers, but in the family; not aliens, but friends, and to be treated as such.

That’s not easy, of course. But what’s the alternative? The problem of growing inequality and the deepening stratification of society won’t fix itself. Politicians and bureaucrats can’t be absolved of responsibility. Then again, neither can we.