Spatiotemporal Evolution and Spatial Equity of Public Service Supply–Demand Matching in Suburban Areas from a Social Sustainability Perspective: A Case Study of Beijing

Coordinating public service supply and demand is essential to urban social sustainability. This study examines ten suburban districts of Beijing at six observation points from 2015 to 2024 and develops an integrated framework encompassing resource endowment, demand pressure, supply–demand matching, and spatial equity. Resource endowment and demand pressure are measured using spatial accessibility and objective weighting methods, while relative matching coefficients, Lorenz curves, and Gini coefficients are employed to evaluate spatial mismatch and equity. The results reveal a shift toward a dynamic polycentric supply pattern, persistent relative undersupply in Tongzhou and Daxing, and dimension-specific deficits in several otherwise balanced districts. Overall spatial equity improved during the study period, although localized mismatches remained. Public service planning should therefore move from uniform expansion toward demand-responsive, place-specific, and service-specific optimization.