Income inequality in the United States has increased since 1960, in part, because of more women entering the workforce and "assortative mating," or the tendency for people to choose mates with similar education levels, according to new research.
People with higher education levels tend to make more money than people with lower education levels. That fact added to an increase in assortative mating and an increase in women working means that household income has increased at a much higher rate for the highly-educated than household income for those with less education.
Put another way, as more women have entered the workforce, the women with college degrees are more likely to marry someone who also has a college degree, thus increasing their household income at a much higher rate than women who entered the workforce with less education and married men with less education.
This was the finding of "Marry Your Like: Assortative Mating and Income Inequality," a working paper by economists Jeremy Greenwood (University of Pennsylvania), Nezih Guner (Markets, Organizations and Votes in Economics), Georgi Kocharkov (University of Konstanz) and Cezar Santos (University of Mannheim).
Their research suggests that in 1960 assortative mating had no impact on income inequality. Additionally, they found that if there were no assortative mating (if people were randomly matched with partners without regard to education level), there would have been no increase in income inequality from 1960 to 2005. Their finding, the paper notes, is consistent with the findings of previous research on the link between assortative mating and inequality.
Rich Morin, senior editor at the Pew Research Center's Social & Demographic Trends Project, wrote a review of the paper for Pew's Factank blog.
"For example, in 1960," he wrote, "a husband and wife, each with a high school education, would earn about 103% of the average household income. But in 2005, that same couple would earn only about 83% of the average. At the other end of the education spectrum, a couple in which both partners had done post-graduate work earned about 176% of the mean household income in 1960 but a whopping 219% in 2005."
Inequality has become a controversial political topic recently. Democrats have suggested they will try to make it a key issue in the 2014 elections. In a December speech, President Barack Obama called it "the defining issue of our time." In his Tuesday State of the Union Address, though, he only mentioned inequality three times, preferring the theme of "opportunity," which he mentioned 12 times.