Industrial collaborative agglomeration and green economic efficiency—Based on the intermediary effect of technical change

Industry upgrading and structure transformation are important methods for the green and sustainable development. This paper utilizes urban panel data from China spanning the years 2009–2022 to investigate the impact of manufacturing and producer services collaborative agglomeration on green economy efficiency. Additionally, it examines the mediating effect of three modes of technical change: domestic technological stock, international technology transfer, and innovation absorptive capacity. The key findings are summarized as follows: (1) The impact of Industrial collaborative agglomeration (ICA) on green economy efficiency follows a U-shaped curve relationship, when the degree of ICA is below the inflection point (1.4022), it negatively affects green economy efficiency. However, when the degree surpasses that point, it demonstrates a positive impact. (2) Domestic technological stock and international technology transfer act as mediating variables between ICA and green economy efficiency. Advancements in domestic technology innovation and increased international technology transfer contribute to a positive effect of ICA on green economic efficiency.