As urban decline is accelerating due to land imbalance, population decline, and aging, this study empirically analyzes the impact of urban compactness and connectivity on the level of social and economic vitality, focusing on small and medium-sized ci...
As urban decline is accelerating due to land imbalance, population decline, and aging, this study empirically analyzes the impact of urban compactness and connectivity on the level of social and economic vitality, focusing on small and medium-sized cities. To this end, hierarchical clustering and Generalized Additive Model(GAM) were conducted on small and medium-sized cities with a population of 50,000 to 500,000 people, using urban structure indicators (per capita housing area, built-up area, access to neighborhood facilities, population movement, freight movement, and transportation connectivity).
The study consists of two main steps. First, the structural characteristics of small and medium-sized cities were categorized based on compactness and connectivity indicators. The cluster analysis resulted in four clusters: high-density, high-connected small and medium-sized cities near metropolitan areas (Cluster A), cities with relatively strong logistics functions (Cluster B), low-density, low-connected small and medium-sized cities (Cluster C), and highly connected small and medium-sized cities with high transportation connectivity and freight movement indicators (Cluster D).
Second, a Generalized Additive Model (GAM) was applied to examine the effects of these structural indicators on social vitality (floating population) and economic vitality (per capita card sales). The global GAM results showed that both compactness and connectivity significantly influenced vitality, with explanatory power of 69.6% for social vitality and 73.9% for economic vitality, indicating that urban structure is a determinant of urban vitality. Then conducted a Local GAM analysis with conditional smoothing by cluster, and found that the influence and response of each structural indicator differed across clusters. Specifically, Cluster A showed a non-linear (S-shaped) response, with population mobility hindering vitality beyond a certain level, and access to neighborhood amenities negatively affecting social vitality, suggesting that excessive density or connectivity limits vitality. Cluster B was characterized by poor transferability of structural conditions to function, with no significant association with vitality across most structural indicators. Cluster C found that housing per capita had a positive effect on social vitality and a negative effect on economic vitality, suggesting that in places where physical housing is available, it is a positive factor for population growth but a constraint on the expansion of the consumption base. Cluster D shows structural differentiation, with social vitality being more sensitive to compactness and economic vitality being more sensitive to connectivity.
These findings suggest that urban vitality is not determined by the absolute level of any single indicator, but rather functions differently according to a city’s structural type and contextual conditions. Accordingly, efforts to enhance urban vitality should adopt a context-sensitive approach, grounded in a precise diagnosis of local structural characteristics and response mechanisms. This study is subject to several limitations. First, it is based on cross-sectional data and therefore does not account for long-term trends in urban vitality. Second, the analysis relies primarily on quantitative indicators, which may not fully capture residents’ lived experiences or contextual subtleties. Third, the cluster-level approach limits the extent to which city-specific policy contexts are reflected. Nevertheless, this study empirically analyzes the non-linear relationship between urban structure and vitality. It also compares the structural heterogeneity of small and medium-sized cities and how vitality forms across different types. It is also significant in that it confirms the importance of context-based interpretation of each region by analyzing the structural responses to compactness and connectivity of urban structure.