统计研究

网络基础设施作为数字经济发展的“中枢节点”和“传输纽带”，对激活城市包容性增长与绿色偏向发挥着重要作用。本文将宽带中国战略视为网络基础设施的外生政策冲击，并利用修正后的引力模型、非期望产出的Super-EBM模型，对知识流动与包容性绿色增长效率进行测算。在此基础上，从知识流动视角对网络基础设施建设与城市包容性绿色增长的关系进行深入探索。研究发现，第一，网络基础设施建设对城市包容性绿色增长具有显著促进作用，且该作用在非资源型城市更为明显；第二，知识流动是网络基础设施促进城市包容性绿色增长的重要中介机制，该中介机制通过地形起伏度、方言多样性指数等工具变量系统识别后仍然成立；第三，绿色创新与创业活力是网络基础设施驱动城市包容性绿色增长的调节中介机制，两者均能够强化知识流动对城市包容性绿色增长的促进作用；第四，城市间知识流动能够进一步推进市场有效整合，使得网络基础设施对城市包容性绿色增长的机制影响存在明显的链式传导作用。上述结论更深层次地打开了知识流动传导机制黑箱，能够为网络基建规划与城市转型方案提供重要借鉴和政策启示。

Network infrastructure, as the central node and transmission link for the development of the digital economy, plays an important role in activating the inclusive growth and green bias of cities. The article considers the broadband China strategy as an exogenous policy shock to network infrastructure and measures the efficiency of knowledge flows and inclusive green growth using a modified gravity model and a Super-EBM model with non-expected outputs. Based on the above, the relationship between network infrastructure construction and inclusive green growth in cities is explored in depth from the perspective of knowledge flow. It finds that, firstly, network infrastructure construction plays a significant role in promoting inclusive green growth in cities, which is more obvious in non-resource-based cities. Secondly, knowledge flow is an important mediating mechanism for network infrastructure to promote inclusive green growth in cities, which still holds after being systematically identified by instrumental variables such as topographic relief and dialect diversity index. Thirdly, green innovation and entrepreneurial vitality are moderating mediators of network infrastructure driving inclusive green growth in cities, both of which can enhance the contribution of knowledge flows to inclusive green growth in cities. Fourthly, inter-city knowledge flow can further promote effective market integration, which makes the mechanism of the impact of network infrastructure on urban inclusive green growth have a significant chain transmission effect. The conclusions unlock the transmission mechanism of knowledge flow and provide reference and policy implications for the further planning of network infrastructure construction and city transformation programs.