Liza Merolla and her husband, Justin Merolla, are among a growing number of couples who met through one of the world’s most expensive dating sites.

They were students at the business school of Columbia University in New York City, where two years of tuition and fees total more than $200,000. It paid off. The Merollas, ages 34 and 36, graduated in 2015 and are living happily ever after in Brooklyn. On Monday, they had their first child, Avery Merolla.

Roughly half of Americans ages 18 to 28 say they use online dating sites, according to Pew Research. Others are finding romance at business schools.

Glenn Hubbard, former dean of Columbia Business School, said he has lost count of the number of business-school weddings he has attended. Statistics seem to support his observations.

Women made up less than 30% of students enrolled in M.B.A. programs during 2005, the year the nonprofit Forté Foundation started to tally gender. Today, about 40% of the students at the top 50 programs are women.