Bruce Sacerdote

A little randomness can go a long way

The following excerpt is from Professor Bruce Sacerdote ‘s article "What to expect when a college assigns students to random roommates".

"Duke University recently announced that first-year students will now be randomly assigned to their dormmates. The goal is to give students a chance to meet and learn from peers from a completely different background. Is this silly social engineering or smart policy?

First, let’s acknowledge that roommates and dormmates matter for students’ social networks. In one study – titled “How Do Friendships Form?” – David Marmaros and I examined email behavior among thousands of college students. First-year roommates exchange 45 times more emails with each other than with a randomly chosen member of the incoming class.


The bonds that students form their first year are long lasting. By senior year, former first year roommates are still emailing each other at 10 times the rate that they would with other students on campus.