Spatial spillover and threshold effects of digital economy on green innovation efficiency-based on provincial level data in China

"Digitization" and "greening" are important directions for China's future economic development. As the frontier technology of economy and society, the digital economy plays an important role in promoting green innovation and development through digitization and intelligent transformation to promote the power and efficiency change of the whole society. Using the panel data of 30 provinces in China from 2011 to 2020, the super-efficiency SBM-DEA model and the entropy value method are used to evaluate China's regional green innovation efficiency and digital economy, respectively. The nonlinear and spatial spillover effects of the digital economy on green innovation efficiency were investigated based on the fixed effect model, threshold effect model, and spatial econometric model. The results show that (1) the digital economy has a facilitating effect on regional green innovation efficiency, and this facilitating effect is regionally heterogeneous. (2) There is a double threshold effect of the digital economy on green innovation efficiency, and the impact of the digital economy on green innovation efficiency has an overall U-shaped trend. (3) Digital economy and green innovation efficiency have a positive correlation in space, and there is an obvious positive spatial spillover effect of digital economy development on green innovation efficiency. Given the above conclusions, China should improve the construction of digital infrastructure, coordinate the development of a regional digital economy, and formulate differentiated digital economy policies to stimulate the vitality of green innovation and promote the improvement of regional green innovation efficiency.