Abstract: Green technology innovation is the key to achieving carbon neutrality and economic development. This paper provides a quantitative evaluation of 246 policy texts issued in China between 2006 and 2020. A bilateral stochastic frontier model is introduced to capture the impact of green innovation policy and its implementation deviation on green technology innovation. The results are as follows． The annual quantity of environmental innovation policies follows the same trend as the total effectiveness of the policies, while the average effectiveness exhibits a trend of fluctuating upward. There is significant heterogeneity in the effectiveness and sustainability of policy instruments. On average, the implementation and governance benefits of environmental policies make the green technology innovation level 16% higher than the frontier level, while the policy implementation deviation reduces the regional green technology innovation level by 8.3%. The net effect of these two opposing forces makes the actual level of green technology innovation 7.7% above the frontier level. The driving effect of green innovation policies is characterized by a “W-shaped” temporal distribution. It is very necessary to enhance the policy governance effectiveness in central China. In addition, under the influence of industrial structure and economic development, the impact of the intensity of policy implementation on the net effect shows a “U” shape. In financially medium-developed regions, local governments are more motivated to put policies into practice, thus leading to significant “ripple effect” of green innovation. This paper contributes to the dynamic assessment of the governance effects of green innovation policies and provides targeted insights for the development of high-quality of green innovation.

Key words: green technology innovation, policy implementation deviation, bilateral stochastic frontier model, policy quantification