Does Network Externality of Urban Agglomeration Benefit Urban Economic Growth—A Case Study of the Yangtze River Delta

Scholars have conducted a large number of empirical studies on agglomeration externalities and network at the urban scale, but there are relatively few scale. For integrated development Yangtze River Delta (YRD), analyzing impact can provide academic references for agglomerations. The results show that: (1) From 2000 to 2010, average GDP growth rate cities in YRD region showed rapid trend began slow down after showing an outward spatial distribution pattern. (2) 2020, Shanghai’s investment downward diffusion. within slowing from 2015 increased 2015, northwest southeast. other China continuous upward trend, spatially formed characteristic (3) internal that across accelerate economic growth, has greater role promoting indicating “agglomeration externalities” “network scale both promote effect is more obvious. (4) core city Shanghai does not play significant long-term region.