Spatial Effects of Air Passenger Location Entropy on Airports’ Passenger Throughputs: A Case Study of Multi-Airport System in the Yangtze River Delta Region, China, with Implications for Sustainable Development

This study systematically evaluates the spatial effects and driving mechanisms of Passenger Throughput (PT) within the Multi-airport System (MAS) of the Yangtze River Delta (YRD) region in China, using data from 22 cities between 2011 and 2019. Initially, the Air Passenger Location Entropy (APLE) index is introduced to quantify the spatial agglomeration within the MAS. Subsequently, both global and local Moran’s I indices are employed to assess the spatial autocorrelation of PT. Finally, Lagrange Multiplier (LM) tests, Wald test and Likelihood Ratio (LR) tests are utilized to select the appropriate spatial econometric model under different spatial weight matrices. Key findings include: (1) Air transport activity within the MAS exhibits a dynamic trend toward intensified spatial agglomeration and enhanced regional equilibrium; (2) APLE with higher value primarily concentrated in the southeastern coastal cities; (3) APLE has a significant positive impact on PT, with a 1% increase in APLE, leading to an average increase of 0.429% in PT; and (4) in cities with a well-developed air transport system, PT is predominantly influenced by APLE (0.915), whereas in cities with less robust air transport infrastructure, PT is more strongly influenced by tertiary industry value added (0.839) and GDP (0.442). These findings underscore the pivotal role of spatial dynamics in shaping PT and emphasize the necessity of spatially informed policy interventions to foster balanced regional development, strengthen system resilience, and advance the sustainable evolution of the MAS.