title: Competition between collective and individual dynamics.
abstract: Linking microscopic and macroscopic behavior is at the heart of many natural and social sciences. This apparent similarity conceals essential differences across disciplines: Although physical particles are assumed to optimize the global energy, economic agents maximize their own utility. Here, we solve exactly a Schelling-like segregation model, which interpolates continuously between cooperative and individual dynamics. We show that increasing the degree of cooperativity induces a qualitative transition from a segregated phase of low utility toward a mixed phase of high utility. By introducing a simple function that links the individual and global levels, we pave the way to a rigorous approach of a wide class of systems, where dynamics are governed by individual strategies.
authors.affiliation: Université de Lyon, Laboratoire de Physique, Ecole Normale Supérieure Lyon and Centre National de la Recherche Scientifique, 46 Allée d'Italie, F-69007 Lyon, France.
authors.forename: Sébastian
authors.initials: S
authors.lastname: Grauwin
authors.forename: Eric
authors.initials: E
authors.lastname: Bertin
authors.forename: Rémi
authors.initials: R
authors.lastname: Lemoy
authors.forename: Pablo
authors.initials: P
authors.lastname: Jensen