Low-carbon transition effects of the digital economy in Chinese cities—the perspectives of green technology innovation and energy efficiency

Under the impact of the digital economy (DE), what new trends will carbon emissions (CE) exhibit? This paper centers on this core question and, from the dual perspectives of green technology innovation (GTI) and energy efficiency (EE), elucidates the theoretical mechanism through which the digital economy drives the low-carbon transition effect (LCTE) in cities. Empirical validation is conducted using sample data from Chinese cities between 2010 and 2023. The findings reveal that: (1) there is a significant inverted U-shaped relationship between DE and CE, with LCTE emerging after the DE inflection point. This conclusion remains robust after rigorous testing, including instrumental variable methods and alternative regression models. (2) Mechanism tests confirm that DE fosters the LCTE through the mediating channels of GTI and EE. (3) Heterogeneity analysis indicates that DE’s LCTE is more pronounced in eastern regions, cities with stringent environmental regulations, and those with lower digital divides. Based on these findings, the study proposes recommendations: enhancing support for the digital industry, particularly by tilting DE policies toward western regions, cities with weak environmental supervision, and those with significant digital divides, should be a future priority. Additionally, it is essential to refine policy guidance for green technology innovation and energy efficiency, leveraging digital technologies to improve the precision of policy support.