Nearly 3,000 users agreed and filled out extensive questionnaires, which asked about their daily routines, political views and general state of mind.

Half the users were randomly assigned to deactivate their Facebook accounts for a month, in exchange for payment. The price point for that payment was itself of great interest to the researchers: How much is a month’s access to photos, commentary, Facebook groups, friends and newsfeeds worth? On average, about $100, the study found, which is in line with previous analyses.

During the month of abstinence, the research team, which included Sarah Eichmeyer and Luca Braghieri of Stanford, regularly checked the Facebook accounts of the study’s subjects to make sure those who had agreed to stay away had not reactivated them. (Only about 1 percent did.)

The subjects also regularly received text messages to assess their moods. This kind of real-time monitoring is thought to provide a more accurate psychological assessment than, say, a questionnaire given hours or days later.

Some participants said that they had not appreciated the benefits of the platform until they had shut it down. “ What I missed was my connections to people, of course, but also streaming events on Facebook Live, politics especially, when you know you’re watching with people interested in the same thing,” said Connie Graves, 56, a professional home health aide in Texas, and a study subject. “And I realized I also like having one place where I could get all the information I wanted, boom-boom-boom, right there.”

She and her fellow abstainers all had access to Facebook Messenger throughout the study. Messenger is a different product, and the research team decided to allow it because it has similarities with other person-to-person media services.

When the month was over, the quitters and control subjects again filled out extensive surveys that assessed changes in their state of mind, political awareness and partisan passion, as well as the ebb and flow of their daily activities, online and off, since the experiment began.