产业集聚与城市用水强度:降低还是提升——基于中国285个地级及以上城市的经验分析

基于2006～2016年中国285个地级及以上城市的面板数据,利用动态面板数据的系统GMM方法和面板门限回归模型探究产业集聚形态对城市用水强度的影响。在此基础上,分别引入经济发展水平、基础设施建设水平和就业密度作为门限变量检验集聚形态与用水强度的阶段性特征。研究发现:专业化产业集聚能够实现正向技术溢出并降低城市用水强度;多样化产业集聚同样对城市水资源利用发挥节约效应。不同产业集聚形态与城市用水间的关系在城市规模的调节下,均呈现出明显的区制转换特征;随着经济规模扩张,产业集群渐进饱和,水资源争夺态势加剧,水资源配置效率降低;当城市基础设施有限时,过度集聚超越区域承载能力,引致企业对公共基础设施恶性竞争,产业集聚对城市水资源配置正向溢出效应难以发挥;当就业密度进一步提升时,专业化产业聚集的路径依赖机制可能诱发技术锁定效应;由于多元化的知识基础,多样化产业集聚的劳动力池效应更明显,协同学习能力提升将催生绿色技术进步并发挥节水效应。

Industrial Agglomeration and Urban Water Intensity:Inhibition or Promotion——Based on the Experience Analysis of 285 Prefecture-level Cities or Above in China

Abstract：Based on the panel data from 285 prefecture-level cities or above in China during 2006 and 2016, this article adapts the dynamic panel data model with System GMM estimation method and panel threshold regression model to disclose the effect of the specialized and diversified industrial agglomeration on urban water intensity. On this basis, the stage characteristics of different industrial agglomeration types and water use intensity are tested by introducing economic development level, infrastructure construction level and employment density as the threshold variables. The results indicate that: (1) Specialized industrial agglomeration alleviates the intensity of urban water by realizing positive technology spillover. (2) Similarly, diversified industrial agglomeration reveals a saving role in the process of urban water resource utilization. (3) Under the adjusting effect of urban scale, the relationship between different industrial agglomeration types and urban water intensity shows obvious characteristics of regime switching. (4) With the continued expansion of economic scale, industrial clusters will gradually become saturated, moreover, the situation of water resources competition will intensify, and the allocation efficiency of water resources will be reduced.(5) When urban infrastructure is limited, over-agglomeration exceeds regional carrying capacity, which will lead to vicious competition for public infrastructure and make it difficult to exert the positive spillover effect on urban water resources allocation. （6） In addition, as the employment density increases further, the mechanism of path dependence of specialized industrial agglomeration may induce technology lock-in effect. However, due to the diverse knowledge base, the labor pooling effect of diversified industrial agglomeration is more obvious, meanwhile, the improvement of collaborative learning ability will promote the green technology progress and bring water-saving effect into full play.