Innovation spillovers in production networks: Evidence from the establishment of national high-tech zones

Based on a novel dataset constructed with the supplier-consumer paired sample, this paper uses a difference-in-differences approach to evaluate the impact of national high-tech zones on firm performance. We find that the supplier's sales growth rate increased by about 61.35% after the approval of the national high-tech zone in the place where its largest customer was located. This spillover effect transmitted from the consumer to the supplier could be due to either knowledge spillover or demand expansion. Further study finds that the innovation spillover effect is stronger when the consumer company has a higher switching cost, when the supplier company has a stronger absorption capacity, and when the relationship between the supplier and the consumer is closer. Our paper suggests that the innovation policy effect would be amplified through the supply chain network.