title: Constructing cities, deconstructing scaling laws.
abstract: Cities can be characterized and modelled through different urban measures. Consistency within these observables is crucial in order to advance towards a science of cities. Bettencourt et al. have proposed that many of these urban measures can be predicted through universal scaling laws. We develop a framework to consistently define cities, using commuting to work and population density thresholds, and construct thousands of realizations of systems of cities with different boundaries for England and Wales. These serve as a laboratory for the scaling analysis of a large set of urban indicators. The analysis shows that population size alone does not provide us enough information to describe or predict the state of a city as previously proposed, indicating that the expected scaling laws are not corroborated. We found that most urban indicators scale linearly with city size, regardless of the definition of the urban boundaries. However, when nonlinear correlations are present, the exponent fluctuates considerably.
authors.affiliation: Centre for Advanced Spatial Analysis (CASA), University College London, London, UK e.arcaute@ucl.ac.uk.
authors.forename: Elsa
authors.initials: E
authors.lastname: Arcaute
authors.affiliation: Centre for Advanced Spatial Analysis (CASA), University College London, London, UK Center for Advanced Modeling, The Johns Hopkins University, Baltimore, MD 21209, USA.
authors.forename: Erez
authors.initials: E
authors.lastname: Hatna
authors.affiliation: Centre for Advanced Spatial Analysis (CASA), University College London, London, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Ferguson
authors.affiliation: The Institute for New Economic Thinking at the Oxford Martin School, University of Oxford, Oxford, UK Santa Fe Institute, Santa Fe, MN 87501, USA.
authors.forename: Hyejin
authors.initials: H
authors.lastname: Youn
authors.affiliation: Centre for Advanced Spatial Analysis (CASA), University College London, London, UK Department of Civil Engineering, University of Bristol, Bristol, UK.
authors.forename: Anders
authors.initials: A
authors.lastname: Johansson
authors.affiliation: Centre for Advanced Spatial Analysis (CASA), University College London, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Batty
mesh_terms: D002947:Cities; D016000:Cluster Analysis; D004739:England; D004779:Environment Design; D005843:Geography; D006801:Humans; D011156:Population Density; D012959:Socioeconomic Factors; D014505:Urban Population; D014852:Wales
keywords: city boundaries; power-laws; scaling laws; urban indicators