China's New Environmental Protection Law and Green technology innovation in Resource-Based Enterprises: A Double Machine Learning Approach

The sample was initially sourced from the Guotaian CSMAR database. Following the classification of resource-based industries, companies belonging to the aforementioned 12 sectors were selected. Subsequently, exclude ST companies with abnormal financial conditions, PT companies waiting for delisting, and insolvent enterprises. Finally, to obtain data for the control variables, the stock codes of these companies were matched with the CSMAR database. The final sample comprises 834 firms, yielding a total of 9491 firm-year observations.