Social circles
If you live in a city, you know that a fair amount of your movement around town is social in nature. But how much, exactly? A new study co-authored by MIT researchers uses a novel method to infer that around one-fifth of urban movement is strictly social, a finding that holds up consistently in multiple cities. The study used anonymized phone data that, unlike most data in the field, provides information that can be used to reconstruct both people’s locations and their social networks. By linking this information together, the researchers were able to build a picture indicating which networks were primarily social, as opposed to work-oriented, and then deduce how much city movement was due to social activity. “Adding two data sources — one on the social side and one on the mobility side — and layering them one on top of each other gives you something that’s a little bit...