A century ago, most Americans married young and locally, and to people who were alike in race, religion, culture and geography. This necessarily smaller pool of eligible mates meant that other factors such as intelligence and education played a smaller role than race and religion in choosing a partner.
Among the great achievements of this republic was that, in the decades following World War II, we began to marry with less regard for race, religion and culture. We married later in life and with far fewer geographic restrictions.
One result is that the “marriage market” shifted from small towns to colleges and workplaces. So, educational attainment, not race and religion, became a more important factor.
We see this all around us. It is happily unremarkable to see mixed-race families, or marriages between Methodist and Catholic that were difficult even a half century ago and nearly impossible a century ago (I use examples from my own family). Yet, college grads and high school dropouts seldom marry.
Here is where I get a bit unsettled. You see, this research comes to economics from sociology, anthropology and evolutionary biology. Their interest is in the social and biological changes wrought by these changes to mating patterns.
For factors such as race and religion are uncorrelated with intelligence. Not so with educational attainment. So, if humans are now more likely to mate with people who are more like them in intelligence, there are evolutionary implications that matter greatly to income mobility.
Several important studies come to the same broad conclusion. Changes to assortive mating may, within a few generations, make changes to intelligence in our society, splitting the bell curve of smarts into separate populations.
One of the more interesting papers on the subject attributes almost all the increase in income inequality over the past 50 years to assortive mating, but not through human evolution. As it turns out, better-educated people are considerably more likely to marry before having children, far more likely to be employed and to stay married.
The math is simple. Assortive mating leads to higher levels of income inequality between households because individuals with higher incomes are more likely to marry other high earners, and vice versa.
So it gets back to basics. Choices determine how much schooling we get, where we live, whom we marry and when we bear children. These choices largely decide household earnings.
While it is alluring to wish away the power of choice by blaming foreign competition, racism or bad tax policy for income inequality, those theories do not fit the facts.•
Hicks is director of the Center for Business and Economic Research and a professor of economics at Ball State University. His column appears weekly. He can be reached at firstname.lastname@example.org.