Divergent trajectories of global urbanization: Intra-national spatial inequality and structural mismatch across the Global North and South

Abstract Global urbanization is transforming the spatial organization of land, population, and economic activity, yet these processes rarely proceed synchronously or evenly within national territories. Most global assessments rely on national aggregates or disconnected city samples, obscuring internal territorial inequalities at the scale where spatial planning and resource allocation are largely implemented. This study addresses this scale gap by constructing a globally consistent subnational panel for 2001–2020 that integrates dynamic urban built-up footprints with gridded population and economic output. Subnational administrative units provide a common territorial basis for measuring inequality within countries, rather than representing independent urban cases. We develop an integrated framework combining multi-scale inequality decomposition, within-country spatial inequality measurement, multidimensional decoupling assessment, and longitudinal trajectory classification to identify the dominant scale of global urban inequality, characterize structural mismatches among urban land, population, and economic activity, and trace their longitudinal trajectories across the Global North and South. The results establish within-country disparities as the dominant component of global urban spatial inequality, indicating that national averages conceal substantial and enduring territorial polarization. They further reveal a systematic North–South asymmetry: Northern inequality is more strongly associated with inherited patterns of physical expansion and concentrated demographic and economic activity, whereas Southern inequality is more closely associated with population growth and a widening mismatch between population concentration and localized economic output. Across dimensions, national inequality follows persistent and divergent trajectories rather than a uniform path toward convergence. By reconceptualizing global urban inequality as a multidimensional territorial process operating within countries, this study provides a transferable framework for comparative urban research and a empirical basis for differentiated pathways toward equitable and sustainable urbanization.