Echoes of growth: Demographic decoupling and path-dependent legacies in urban expansion across Europe

Urban expansion across Europe increasingly unfolds under heterogeneous demographic conditions. While population change has long structured interpretations of urban growth, recent evidence suggests urban expansion no longer adjusts to contemporary demographic dynamics as it once did. This article examines urban expansion across 181 European Functional Urban Areas between 2000 and 2025, with particular attention to changes after 2015. Using stacked regression models, it identifies an acceleration in urban expansion after 2015 alongside evidence of demographic decoupling. A complementary cross-sectional analysis conditions post-2015 urban expansion on earlier development trajectories, allowing deviations from historically expected patterns to be identified. The article refers to this pattern as echo urbanisation, a benchmark-relative diagnostic that captures urban expansion exceeding what prior development paths and demographic change would predict. The results show that echo urbanisation cuts across population growth and decline and is not confined to post-socialist Europe, pointing to a broader European regime of demographically decoupled urban expansion, within which echo-driven expansion is widespread. It complements existing expansion indicators by flagging cities accelerating beyond expected paths that conventional density, sprawl or demographic-mismatch measures may miss.