Threshold effect of industrial agglomeration on carbon productivity in China's Yangtze River economic belt: a perspective of technical resourcing.

The Yangtze River Economic Belt's industrial layout is characterized by industrial agglomeration. However, industrial agglomeration, while promoting economic development, has an uncertain impact on the ecological environment. This research studies the threshold impacts of pollution-intensive industrial agglomeration and green-based industrial agglomeration on the carbon productivity of the Yangtze River Economic Belt through the panel threshold regression models to find the "optimal industrial agglomeration scale." The results of the "optimal industrial agglomeration scale" show that under the existing economic conditions, only if pollution-intensive industrial agglomeration is controlled within a reasonable range can it contribute to carbon productivity. Green-based industries can only enhance carbon productivity when the scale of agglomeration reaches a certain value. In addition, this paper also points out that along the Yangtze River Economic Belt, regions with high agglomeration of green industries should consider investing more technological resources in emerging technologies that use clean energy as a production condition. In contrast, regions with high agglomeration of pollution-intensive industries should focus on improving existing technologies in which traditional energy sources are used as production conditions to increased carbon productivity.