Measurement and Influencing Factors of Urban Network Externalities in Yangtze River Delta Urban Agglomeration

Promoting the free and orderly flow of factors and improving urban network externalities are inherent requirements for the high-quality integrated development of regional economies. Existing research has mostly explored network externalities from the perspective of a single-factor flow, with insufficient attention to the influencing factors of network externalities. This paper constructed a multidimensional factor flow network and used the Cobb–Douglas production function and multiscale geographical weighted regression (MGWR) model to test urban network externalities. Also, Geodetector was used to identify the formation mechanism of the spatial differentiation of network externalities. The following findings are obtained in this study: (1) High-level factor flows are mostly concentrated in the eastern region of the Yangtze River Delta, and the intensity of factor flows in the urban pairs consisting of Shanghai, Nanjing, Hangzhou, Suzhou, and Hefei is significantly higher than that in other urban pairs. (2) Economic development is synergistically promoted by network externalities and production factors such as labor, capital, and technology. Coefficients of network externality exhibit a layered distribution characteristic that decreases gradually from east to west. (3) The spatial differentiation of network externalities is jointly influenced by multiple factors, among which the overall upgrading industrial structure level is the dominant factor. This study helps improve the theory of urban network externalities and provides a scientific basis for formulating relevant policies to promote the high-quality integrated development of the Yangtze River Delta integration.