How does financial and manufacturing co-agglomeration affect environmental pollution? Evidence from China

To investigate the direct influence and mechanism of China's financial and manufacturing co-agglomeration on environmental pollution, we constructed a panel data regression model incorporating mediating and threshold effects with the panel data of 285 prefecture-level cities from 2009 to 2019. The results showed a higher co -agglomeration level significantly increased environmental pollution. The transmission and upgrading from secondary to tertiary industries exhibited a remarkable intermediary role, yet the credit scale formed a nonlinear threshold effect. Both industrial structure optimization and credit scale expansion contributed to environmental protection. Nevertheless, the path of "industrial co-agglomeration -> technological progress -> environmental protection" was not obvious, and the positive externalities of technology need to be strengthened. These findings provide viable insights for the implementation of financial and manufacturing integration and green development.