城市创新行为改善生态效率了吗?——基于空间关联与溢出视角的考察

Does Urban Innovation Improve Ecological Efficiency? Based on the Perspective of Spatial Correlation and Spatial Spillover

文章在理论层面探讨了创新对生态效率的影响机制,并基于城市空间关联与溢出视角,采用我国2007-2016年260个城市面板数据,运用空间计量模型检验了创新对生态效率的影响效应及多维度的城市异质性。进一步地,文章还通过对不同距离阈值上的创新空间溢出效应进行估计,测算了创新空间溢出的距离边界,检验了创新空间溢出驱动城市绿色发展的最佳地理距离区间,从而为增强区域创新合作以提升区域整体绿色发展水平提供了可供参考的量化依据。研究发现:总体而言,创新具有的增长效应、资源与环境效应、结构优化效应是促进城市生态效率改善的重要途径,且产出端创新对生态效率的驱动效应强于投入端创新;但创新对生态效率的影响具有显著的城市异质性,依赖于城市区位、所在城市群、环境政策、资源禀赋、创新能力和市场化水平;城市创新行为具有显著的空间溢出效应,但空间溢出随距离变化呈衰退趋势,350公里以内为创新活动的密集溢出区;生态效率也具有明显的空间溢出效应,经济越发达且联系越紧密、要素流动越自由、创新对生态效率驱动效应越强的地区,生态效率的空间溢出也越强。因此政府应完善创新激励政策、为创新外溢创造良好条件、注重引导创新的方向,并根据区域及城市发展实际,采取差异化的创新驱动绿色发展策略。

Innovation is the core driving force for improving urban ecological efficiency,while it does not have a"green"characteristic deservedly.Meanwhile,with the increasing spatial correlation among cities,the innovation activities and ecological efficiency of one city may create spillover effects to other cities.At present,the academic field still lacks the empirical studies of innovation and its spatial spillover effect on urban green development.From the perspective of spatial correlation and spillover,the paper uses the panel data of 260 cities of China from 2007 to 2016 to empirically test the impact of innovation on ecological efficiency by using spatial econometric model and further investigates the spillover effect of innovation on ecological efficiency and the spillover boundaries.The study finds that:Overall,the growth effect,resource and environment effect and structure optimization effect of innovation are important ways to promote the urban ecological efficiency,and the driving effect of output-oriented innovation on ecological efficiency is stronger than that of input-oriented innovation.The impact of innovation on ecological efficiency presents significant urban heterogeneity,depending on urban location,urban agglomeration,environmental policy,resource endowment,innovation capacity and marketization level.The urban innovation has significant spatial spillover effect while the spatial spillover effect declines with the increasing of distance,and the dense spillover effect of innovation activities is within 350 kilometers.In terms of the spatial spillover of ecological efficiency,regions with more developed economy,greater economic ties,and stronger driving effect of innovation on ecological efficiency always have stronger spatial spillover effect of ecological efficiency.Therefore,the government should improve innovation incentive policies,create good conditions for innovation spillover,pay attention to guiding innovation direction and adopting differentiated innovation driving green development strategies.The novelty of this paper is mainly reflected in the theoretical discussion of the impact mechanism of innovation on ecological efficiency,and application of spatial econometric model to investigate this mechanism.At the same time,compared with the previous studies only analysing one aspect of the spillover effect of the regional ecological efficiency or innovation,this study not only investigates the spatial spillover effect of ecological efficiency,but also test the spatial spillover effect of innovation on ecological efficiency,i.e.,through innovation spillover,connect the urban innovation behavior with the green development level of spatially related cities,which makes up the deficiency that previous studies only estimates the impact of innovation on urban green development from the static level or simply consider the spatial spillover effect of innovation itself.Further,this study estimates the spillover effect of innovation at different distance thresholds,and calculates the distance boundary of innovation spillover,so the optimal geographical distance range for innovation spillover driving urban green development is obtained,which provides a quantitative basis for enhancing regional innovation cooperation to improve the overall green development level of the region.