Since the emergence of dating apps that allow people to look for a partner based on criteria including education, Americans have increasingly been marrying someone more like themselves. That accounts for about half of the rise in income inequality among households between 1980 and 2020, researchers from the Federal Reserve Banks of Dallas and St. Louis and Haverford College found. 

Using data from the Census Bureau’s American Community Survey from 2008 to 2021, when online dating quickly became prevalent, the economists found that women became slightly more selective when choosing partners based on age, while men became slightly more selective based on education. 

But when the researchers compared that with data on married couples from 1960 and 1980, they found that people in the recent period increasingly went for partners with the same wage and education levels. And while many people married someone of the same ethnicity, people became less and less selective on race over time.

Who people marry has a major impact on household income. The research shows that the two main contributors to inequality through the selection of a future spouse are education and skills. They are followed, to a much lesser extent, by income and age, while race plays a relatively inconsequential role, co-author Paulina Restrepo-Echavarría, an economic policy advisor at the St. Louis Fed, said in a blog post describing the paper.

Overall, the predominance of online apps to find a future partner has led to a 3-percentage-point increase in the Gini coefficient — a widely used measure of income inequality, the research shows.

“We find that the increase in income inequality over the past half a century is explained to a large extent by sorting on vertical characteristics, such as income and skill, and their interaction with education,” the economists wrote in their paper.