She studied U.S. data from roughly 1990 to 2006 on the marital status of individuals between 21 and 30 years old from the Current Population Survey, along with Federal Communications Commission reports on the spread of broadband. She found marriage rates were slightly higher among college-educated individuals than those without college degrees.

“In recent decades, we have observed important transformations in the marriage market,” Ms. Bellou said. For one thing, more young people are seeking marriage partners on the Internet, and relying less on family and friends for such introductions.

The Internet’s effect on the marriage market could be just as transformative as its effect on matching employers and job-seekers, Ms. Ballou said, given “access to an expanding set of potential partners,” while preserving “a degree of anonymity” for the searcher. But those very characteristics also could undermine the strength of Internet-made matches.