title: Redrawing the map of Great Britain from a network of human interactions.
abstract: Do regional boundaries defined by governments respect the more natural ways that people interact across space? This paper proposes a novel, fine-grained approach to regional delineation, based on analyzing networks of billions of individual human transactions. Given a geographical area and some measure of the strength of links between its inhabitants, we show how to partition the area into smaller, non-overlapping regions while minimizing the disruption to each person's links. We tested our method on the largest non-Internet human network, inferred from a large telecommunications database in Great Britain. Our partitioning algorithm yields geographically cohesive regions that correspond remarkably well with administrative regions, while unveiling unexpected spatial structures that had previously only been hypothesized in the literature. We also quantify the effects of partitioning, showing for instance that the effects of a possible secession of Wales from Great Britain would be twice as disruptive for the human network than that of Scotland.
authors.affiliation: Senseable City Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America.
authors.forename: Carlo
authors.initials: C
authors.lastname: Ratti
authors.forename: Stanislav
authors.initials: S
authors.lastname: Sobolevsky
authors.forename: Francesco
authors.initials: F
authors.lastname: Calabrese
authors.forename: Clio
authors.initials: C
authors.lastname: Andris
authors.forename: Jonathan
authors.initials: J
authors.lastname: Reades
authors.forename: Mauro
authors.initials: M
authors.lastname: Martino
authors.forename: Rob
authors.initials: R
authors.lastname: Claxton
authors.forename: Steven H
authors.initials: SH
authors.lastname: Strogatz
mesh_terms: D000465:Algorithms; D003142:Communication; D005843:Geography; D006801:Humans; D012606:Scotland; D012919:Social Behavior; D013685:Telecommunications; D006113:United Kingdom; D014852:Wales