  In recent decades the world has experienced rates of urban growth
unparalleled in any other period of history and this growth is shaping the
environment in which an increasing proportion of us live. In this paper we use
a longitudinal dataset from Foursquare, a location-based social network, to
analyse urban growth across 100 major cities worldwide.
  Initially we explore how urban growth differs in cities across the world. We
show that there exists a strong spatial correlation, with nearby pairs of
cities more likely to share similar growth profiles than remote pairs of
cities. Subsequently we investigate how growth varies inside cities and
demonstrate that, given the existing local density of places,
higher-than-expected growth is highly localised while lower-than-expected
growth is more diffuse. Finally we attempt to use the dataset to characterise
competition between new and existing venues. By defining a measure based on the
change in throughput of a venue before and after the opening of a new nearby
venue, we demonstrate which venue types have a positive effect on venues of the
same type and which have a negative effect. For example, our analysis confirms
the hypothesis that there is large degree of competition between bookstores, in
the sense that existing bookstores normally experience a notable drop in
footfall after a new bookstore opens nearby. Other place categories however,
such as Airport Gates or Museums, have a cooperative effect and their presence
fosters higher traffic volumes to nearby places of the same type.
