Study on the Impact of Innovative Industrial Cluster Policies on Breakthrough Innovation in Enterprises

Breakthrough innovation serves as a vital source for enterprises to achieve critical technological advancements and foster new productive forces. However, systematic empirical evidence remains scarce regarding whether and through which mechanisms innovative industrial clusters, as policy instruments, can promote breakthrough innovation within enterprises. Therefore, using the 2013 pilot policy for innovative industrial clusters as a natural experiment, this study employs data from Shanghai and Shenzhen A-share listed companies between 2008 and 2021. Breakthrough innovation is measured by the proportion of highly cited patents (those in the top 1% and top 10% by citation count) within a five-year rolling window. A multi-period difference-in-differences model is constructed to identify the causal effect of cluster policies on corporate breakthrough innovation. The findings reveal that the innovative industrial cluster policy significantly enhances breakthrough innovation: the intensity of breakthrough innovation increases by an average of 34.74%, and the probability of generating highly cited patents rises by 3.8 percentage points. Dynamic effects indicate that the policy impact exhibits lag and accumulation, typically peaking in the third to fourth year after implementation. Mechanism tests reveal knowledge agglomeration and collaborative innovation networks as primary transmission channels: the former enhances innovation output by boosting inter-firm knowledge sharing and R&D collaboration, while the latter accelerates technology diffusion and spillovers through strengthened upstream-downstream industrial chain linkages. Heterogeneity analysis further indicates that policy effects are more pronounced for large enterprises, high-tech industries, and central regions: effects increase by 22.7% in eastern regions, 170.5% in central regions, and are insignificant in western regions. This study provides micro-level causal evidence demonstrating how innovative industrial cluster policies promote breakthrough innovation among enterprises, offering empirical support for optimizing cluster policies.