信息基础设施建设能否提升城市绿色创新水平——基于长江经济带108个地级市的实证分析

Can Information Infrastructure Construction Promote Urban Green Innovation:Empirical Analysis Based on 108 Prefecture-level Cities in Yangtze River Economic Belt

绿色创新是推动城市经济绿色高质量发展的重要动力。以“宽带中国”示范政策作为信息基础设施建设的一项准自然实验,基于长江经济带108个地级市面板数据,使用多时点双重差分模型和空间双重差分模型,系统考察了“宽带中国”示范政策对城市绿色创新的直接效应、间接效应和空间效应。研究发现:信息基础设施建设显著提升了城市绿色创新水平,经过异质性处理效应等一系列检验后结果仍然稳健,且这一提升效应在长江经济带下游城市、重点城市、科教资源丰富的城市中表现更为明显。机制检验表明,信息基础设施建设通过人才集聚效应、互联网水平提升效应和数字金融助推效应提高城市的绿色创新水平。空间双重差分结果表明,信息基础设施建设对城市绿色创新产生空间溢出效应,政策效应同时受到经济相似、地理邻近城市的影响。研究结论为进一步推进信息基础设施建设赋能城市绿色创新发展提供了经验借鉴。

Green innovation is an important driving force to promote the green and high-quality development of urban economy.Taking the“Broadband China”demonstration policy as a quasi-natural experiment for information infrastructure construction,based on panel data of 108 prefecture-level cities in the Yangtze River Economic Belt,this paper systematically investigates the direct,indirect and spatial effects of the“Broadband China”demonstration policy on urban green innovation using the staggered difference-in-difference model and the spatial difference-in-difference model.The study finds that information infrastructure construction significantly improves the level of green innovation in cities,and the results remain robust after a series of tests including heterogeneity treatment effects.This improvement effect is more obvious in cities in the lower reaches of the Yangtze River Economic Belt,key cities,and cities rich in scientific and educational resources.The mechanism test shows that information infrastructure construction improves the green innovation level of cities through the talent clustering effect,the Internet level improvement effect,and the digital finance promotion effect.The spatial double difference results show that information infrastructure construction has a spatial spillover effect on urban green innovation,and the policy effect is simultaneously influenced by the economic similarity and geographical proximity of cities.The findings of the study provide empirical insights for further promoting the development of information infrastructure to strengthen urban green innovation.