Service-led growth in airport economic zones: A multi-period DID analysis of China's asymmetric policy impacts

Abstract

This study employs a multi-period Difference-in-Differences (DID) model to analyze the impact of the establishment of 22 national-level airport economic zones in China on firm agglomeration and investment growth within these regions. The results indicate that the establishment of airport economic zones has significantly promoted the growth of both the number of firms and capital investment, particularly within the service sector. However, further robustness checks reveal that only the significant impact on the service sector is consistent and valid. Sub-sector analysis shows that both business services and professional technical services are significantly affected, but only the agglomeration effect in the business services sector is confirmed by robustness tests. The study also finds that the annual number of airport aircraft movements and urban fixed asset investment have a significant positive effect on firm agglomeration. Based on these findings, this paper proposes policy recommendations such as optimizing the air transport network and improving infrastructure development. It also highlights the study's limitations and suggests that future research could expand the sample and methods to enhance the reliability of the results.