Spatial Equilibrium Allocation of Urban Large Public General Hospitals Based on the Welfare Maximization Principle: A Case Study of Nanjing, China

This study aims to utilize the new gravity P-median model to conduct an empirical study for the spatial equilibrium layout of general hospitals in the urban area of Nanjing City, based on multiple requirements for spatial equilibrium, involving spatial equity-efficiency, service utility fairness, and utilization efficiency. The major results are as follows: (1) the new layout can achieve the goal of obtaining a proximate, high-quality medical service in 30 min even for those who reside on the outskirts, which is less than the current 65.6 min. Moreover, the new layout corresponds better to the population distribution and traffic network layout. (2) When compared with several typical characteristics of accessibility to hospitals, including severe gradient variation, five high-value centers, and the efficiency orientation in the current layout, the new demonstrates distinctive ones: comparatively moderate accessibility variation; more relatively high-value areas scattered in different parts of the city; more convenient accessibility on the outskirts; a better balance of the equitable appeal from the inhabitants residing in different areas. (3) The new layout can attain spatial equilibrium at a higher level, the representative indices to measure spatial equity, spatial efficiency, chance fairness, and utilization efficiency have been ameliorated by 54%, 13%, 63%, 14%, respectively. The study reveals that: (1) The new gravity P-median model has the validity and practicability in solving facility location and scale configuration problems with high time complexity, under complicated situations due to multiple targets and multi-agent competition. (2) The model can be applied to decision making related to public infrastructure planning in different types of development areas, by setting concerning parameters or making some minor adjustments to the model in different scenarios. Such research can provide some reference for the location-allocation problem of high-grade facilities in metropolises, and support the decision-making basis for urban infrastructure planning