Research on Port-Industry-City Integration and its Spatial Spillover Effects: Empirical Evidence from the Bohai Sea Rim Region

Port-industry-city is a primary carrier of high-quality economic development, and promoting the integration of port, industry and city is an important measure to realize port reform and industry-city integration. Based on the panel data of port-industry-city in the Bohai Rim region from 2012 to 2021, this study used the ITARA-EDAS model, ArcGIS spatial analysis tool and spatial Durbin model to explore the spatiotemporal evolution characteristics and spatial spillover effects of port-industry-city integration. The results show that: (1) The integration of port, industry and city in the Bohai Rim region has significant spatiotemporal differences, and the distribution pattern of "high in the south and low in the north" is more prominent, especially the gradient pattern with core cities as the center and key cities as the support. (2) The economic impact of port-industry-city integration in the Bohai Rim region has an agglomeration-diffusion effect, i.e., port-industry-city integration promotes the agglomeration of factors of production and promotes the growth of the local economy, which results in the restriction of the development of the neighboring regions; at the same time, port-industry-city integration accelerates the investment in the infrastructure of the neighboring regions through the extension of the industrial chain and its functions and leads to the inter-regional mobility of the production factors and regional cooperation. (3) There are significant regional differences in the direct and indirect effects of port-industry-city integration in provincial-level areas, and there are differences in the regression results with those in the Bohai Rim region. That is, the integration of port, industry and city in Liaoning and Shandong has a significant positive spatial spillover effect, while the economic impact of port-industry-city integration in the Tianjin-Hebei region has a diffusion boundary.