The Spatial Dynamics of Age Segregation in Seoul

Abstract

This dissertation investigates the spatial dynamics of age segregation in the context of Seoul, South Korea, where rapid population aging intersects with spatial inequalities and policy-driven urban development. Despite the increasing prevalence of age-based spatial segregation in aging societies, theoretical and empirical understandings of its causes, spatial patterns, and resulting vulnerabilities remain limited. To address this gap, this dissertation challenges conventional interpretations by conceptualizing age segregation not merely as a natural consequence of demographic aging or individual residential preference, but as a structurally embedded form of spatial inequality shaped by institutional intervention and urban development patterns. Building on this conceptualization, this dissertation develops an interpretive framework that combines both procedural and substantive definitions of segregation. Through this framework, this dissertation aims to expand academic understanding of the causes of age segregation and its implications for the well-being of older adults, while also offering policy insights for urban planning and governance. Empirical analysis is conducted across three integrated chapters. Chapter 3 applies a Difference-in- Differences (DID) approach using spatial-temporal data to assess how government-led housing supply policies, particularly the large-scale public land developments and targeted housing supplying policy implemented after 2010, have contributed to the formation of older adult-concentrated areas and reshaped residential mobility patterns across age groups. The findings indicate that these policies significantly facilitated the inflow of younger adults to newly developed areas, while leaving older adults behind in existing neighborhoods, leading to the reinforcement of Residential Age Segregation. The spatial immobility of older adults, despite their structural advantage in housing assets, is revealed as a consequence of institutional exclusion, not merely personal preference. Chapter 4 shifts focus to the consequences of age segregation by distinguishing between Residential Age Segregation and Activity Age Segregation, examining their differential effects on older adults’ activity levels using OD-based non-commuting trip data. The study finds that Residential Relative Age Concentration consistently suppresses non-commuting activity levels among older adults, regardless of trip purpose. In contrast, Activity Relative Age Concentration has a positive effect on their activity levels, with its impact varying by trip purpose. While it enhances activities related to cultural and commercial facilities, it shows no significant effect on trips to senior welfare facilities. These findings underline the spatial exclusion mechanisms and provide empirical validation for the dual effect of segregation in urban aging environments. Chapter 5 proposes a policy response to mitigate the adverse effects of age segregation by optimizing the spatial allocation of Senior Welfare Housing. Utilizing a metaheuristic multi-objective optimization algorithm, the study identifies optimal locations for three housing types, Subsidized, Affordable, and High-End senior housing, based on both accessibility to urban facilities and existing levels of age segregation. The results demonstrate that including age segregation as a decision variable alongside facility accessibility not only alleviate age segregation but also enhances older adults' activity levels. Notably, the strategy of co-optimizing for both accessibility and age integration produces synergistic policy outcomes, suggesting that spatial inclusion and activity promotion can be pursued simultaneously. Furthermore, the analysis identifies the most efficient scenarios for each housing type by examining variations in accessibility metrics, offering practical guidance for differentiated policy design. Overall, this dissertation contributes to the theoretical discourse on urban segregation by reframing age segregation as a multidimensional process, structurally reinforced by housing policy and neighborhood disparities. It provides robust empirical evidence that spatial age segregation produces apparent constraints on older adults’ mobility and social participation. The findings suggest that urban housing policy should give more consideration to spatial inequality and support greater interaction between different age groups. Through its integrative framework and data-driven methodology, this dissertation offers actionable insights for scholars, planners, and policymakers confronting the spatial challenges of rapidly aging urban societies.