城市集聚经济的多维性及其实证检验

Multi-Dimensional Nature and Empirical Test on Urban Agglomeration Economies

城市集聚经济具有多维性，城市经济活动集聚的不同维度特征都会对集聚经济效应的大小产生影响。本文构建了包含规模效应、密度效应和结构效应三个维度的城市集聚经济综合分析框架，利用中国地级及以上城市2006—2010年面板数据，分别检验了城市集聚经济的三种效应。研究结果发现：在样本范围内，虽然规模效应表现出显著倒U型特征，但是结合最优值在样本区间的分布来看，规模效应基本支持了城市规模越大生产率越高的观点，弹性系数约为1．66％～1．94％；密度效应表现出显著的倒u型特征，按城区总人口比建成区面积的最优城市人口密度值约为1．30万人／平方公里；结构效应在劳均产值模型中，表现出显著的倒U型特征，在工资模型中表现出显著的正向关系。文章对研究结果做了稳健性分析及进一步解释，最后进行了总结并得到关于中国城镇化和城市发展的启示。

Urban agglomeration economies are of multi-dimensional nature, and different dimensions of urban agglomerative characters can affect the agglomeration economies. This article builds an analysis framework of urban agglomeration economies including size effect, density effect and structure effect. And then, using panel data of China＇s Prefecture-level and above cities between 2006 and 2010, this article studies the three effects. This paper found that in the sample range, although size effect shows a significant inverted U-shape, the result still supports the view of ＂larger scale, more productivity＂ because the optimum scale is near the maximum values of the sample, additionally the elasticity is about 1.66~//00--1.94~//oo. Density effect shows significant inverted U-shape, and the optimum density gauged by total urban population divided by urban built-up area is about 13 thousand people per square kilometers. To structure effect, it shows significant inverted U-shape in the model of product per labor, and it only shows positive relationship in the wage model. The article further conducts a robust analysis and gives some further explanations, and at last, gets some practical enlightenment for China＇s urbanization and urban development.