Diversity in decline: The changing suburban fortunes of Tokyo Metropolis

Abstract The suburban territory of Tokyo Metropolis experiences new path-dependent, multifaceted shrinking processes, especially in outer reaches, which are considered a product of synchronized changes in socio-demographic, economic, and political and administrative (fiscal) dimensions. Outer suburban shrinkage is an urgent policy and planning issue for Tokyo's suburban sustainability while Tokyo itself emerges as something of a frontier case globally. We analyze different growth/decline transformation types of Tokyo's suburban municipalities in both pre-bubble growth and post-bubble shrinkage periods with the combined use of Principal Component Analysis and Cluster Analysis, and identify their different trajectories in the contextual transition from growth to shrinkage. By making direct comparisons between growth and shrinkage from a long-term evolutionary perspective, we identify the following: 1) outer suburban impoverishment, 2) different processes of suburban shrinkage from suburban growth, and 3) outer suburban divergence. Suburban shrinkage is revealed as more complicated than suburban growth, generating equally complex challenges for policy responses that will soon reverberate globally. In conclusion, we underline the importance for policy makers worldwide to understand the specificities of outer suburban shrinkage even during periods of suburban growth in order to ensure suburban resilience across different phases of urbanization.