Coupled and coordinated evolution of digital economy and green innovation in Yangtze River Delta region and policy recommendations

The digital economy and green innovation have become crucial pathways for driving economic transformation and upgrading while achieving sustainable development. This paper constructs an indicator system for the digital economy and green innovation based on the entropy weight method. It employs techniques such as the coupling coordination degree model and geographic detector to examine the spatio-temporal evolution and influencing factors of the coupling coordination degree between the digital economy and green innovation in the Yangtze River Delta region. The findings reveal: (1) Overall, the levels of digital economy and green innovation in the study area show an upward trend, with green innovation surpassing digital economy in level but growing at a slower rate. (2) Temporally, their coupling coordination degree has continuously improved, advancing from barely coordinated to moderately coordinated. Among provinces, the ranking from highest to lowest is: Shanghai, Zhejiang, Jiangsu, and Anhui. (3) Spatially, the coupling coordination exhibits distinct non-equilibrium characteristics, forming a "core-periphery" structure. Its spatial evolution features the gradual formation of a Z-shaped pattern centered on Shanghai, supported by Hefei, Nanjing, Changzhou, Wuxi, Suzhou, Jiaxing, Hangzhou, Shaoxing, and Ningbo. (4) Factors influencing their coupling coordination, ranked by impact from highest to lowest, are: economic development level, openness to the outside world, human capital, industrial structure, and government support. Significant two-factor interaction effects exist among these influencing factors. Corresponding policy recommendations are proposed for different provinces to continuously support the coordinated evolution of the digital economy and green innovation in the Yangtze River Delta region.