title: A simple generative model of collective online behavior.
abstract: Human activities increasingly take place in online environments, providing novel opportunities for relating individual behaviors to population-level outcomes. In this paper, we introduce a simple generative model for the collective behavior of millions of social networking site users who are deciding between different software applications. Our model incorporates two distinct mechanisms: one is associated with recent decisions of users, and the other reflects the cumulative popularity of each application. Importantly, although various combinations of the two mechanisms yield long-time behavior that is consistent with data, the only models that reproduce the observed temporal dynamics are those that strongly emphasize the recent popularity of applications over their cumulative popularity. This demonstrates--even when using purely observational data without experimental design--that temporal data-driven modeling can effectively distinguish between competing microscopic mechanisms, allowing us to uncover previously unidentified aspects of collective online behavior.
authors.affiliation: Mathematics Applications Consortium for Science and Industry, Department of Mathematics and Statistics, University of Limerick, Limerick, Ireland; james.gleeson@ul.ie.
authors.forename: James P
authors.initials: JP
authors.lastname: Gleeson
authors.affiliation: Mathematics Applications Consortium for Science and Industry, Department of Mathematics and Statistics, University of Limerick, Limerick, Ireland;
authors.forename: Davide
authors.initials: D
authors.lastname: Cellai
authors.affiliation: Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115;
authors.forename: Jukka-Pekka
authors.initials: JP
authors.lastname: Onnela
authors.affiliation: Oxford Centre for Industrial and Applied Mathematics, Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom;CABDyN Complexity Centre.
authors.forename: Mason A
authors.initials: MA
authors.lastname: Porter
authors.affiliation: CABDyN Complexity Centre,Saïd Business School, University of Oxford, Oxford OX1 1HP, United Kingdom; andInstitute for New Economic Thinking at the Oxford Martin School, University of Oxford, Oxford OX2 6ED, United Kingdom.
authors.forename: Felix
authors.initials: F
authors.lastname: Reed-Tsochas
mesh_terms: D003299:Cooperative Behavior; D006801:Humans; D020407:Internet; D008962:Models, Theoretical; D060756:Social Networking
keywords: branching processes; complex systems