The influence of regional Internet level on firms’ sustainable innovation

Based on secondary data from 31 provinces, cities, autonomous regions, and high-tech manufacturing industry alliance innovation networks in China over 2011–2016, we use the comprehensive feasible generalised least squares method to explore the influence of regional Internet level (RIL) on firms' sustainable innovation (FSI). We find that RIL has an inverted U-shaped relationship with FSI. The RIL has an inverted U-shaped relationship with knowledge flow. Knowledge flow is conducive to the FSI. Knowledge flow plays a mediation role in the inverted U-shaped relationship between the RIL and FSI. In addition, the above results hold in the sample of high-speed rails (HSR) opening, but only the positive relationship between knowledge flow and FSI is supported in the samples of HSR not opening. Our findings provide insightful guidance supported by theoretical underpinning and empirical evidence for different regions to plan and adjust their RIL and HSR rationally, and for high-tech manufacturing firms to use the RIL effectively to enhance knowledge flow and FSI, which has important theoretical and practical significance.