A study looked at how stricter environmental rules in China affected firms' innovation during the 11th Five-Year Plan. They found that tougher regulations led to more patents being filed by industrial companies, supporting the idea that stricter rules can boost innovation. The study also showed that different types of firms were affected in different ways, depending on factors like ownership and size. The results were consistent across various tests, adding to our understanding of how environmental regulations can influence firms' behavior and providing insights for future policies in China.