Can “ Zero waste city” policy promote green technology? Evidence from econometrics and machine learning

The promotion of green technology innovation (GTI) is regarded as an effective way to protect the environment and achieve sustainable development. The “Zero waste city” construction pilot policy (ZWCP), is an important policy for the promotion of waste management, and the achievement of sustainable development and circular economy. The paper explores the effect of ZWCP on GTI using the difference-in-differences model and machine learning. The result shows that ZWCP significantly promotes GTI. In addition, causal forest modeling, a type of machine learning method, similarly validates this result. The mechanism effect suggests that ZWCP promotes GTI by increasing research expenditure and enhancing informational development. The heterogeneity effect suggests that ZWCP is more powerful in promoting GTI when it is implemented in western, low administrative level, and resource-based cities. The paper provides a reference for waste management policies and development of GTI in other countries.