筛选效应、异质企业内生集聚与城市生产率

Selection Effects,Endogenous Agglomeration of Heterogeneous Firms and Urban Productivity

本文通过一个改进的新新经济地理异质企业模型考察城市与企业之间的双向选择机制。理论分析表明,高效企业能制定较低的价格、占有较大的市场,因此倾向进入大城市,而低效企业倾向选择较小的城市;城市越大,对企业的门槛效率要求越高。大城市的企业效率分布曲线相比小城市有较高的左侧截尾,而小城市相对于大城市存在右侧截尾。本文利用中国工业企业微观数据检验企业固定效率在城市间的分布特征,估计显示城市效率门槛随城市规模增长而增长,筛选效应至少相当于传统集聚经济的1/5~2/5,但集聚经济和筛选效应对不同行业的企业影响有所差异。分析还表明,降低区间交易成本有助于城市间效率分布的趋同,市场一体化将提升中小城市生产率、缩小城市间差距。

This paper presents a modified heterogeneous firm model to examine the effects of firm selection/sorting on productivity distribution within and across Chinese cities. Highly productive firms are able to set lower prices, take larger shares of markets, and thus tend to locate in larger cities, whereas less efficient firms tend to locate in smaller cities. The larger the city, the higher is the threshold of productivity required for a firm. The selection effect left-truncates productivity distribution of firms in the large city and the sorting effect right-truncates the distribution of firms in the small city. This paper designs an econometric method and uses China＇s firm level data to estimate the bidirectional selection effects. The results show that the threshold level of firm productivity increases as city size grows and the selection effect is at least one-fifth to two-fifth of agglomeration economies. The paper also demonstrates that lowing transaction cost helps close the threshold gap between large cities and small ones, and that market integration will raise productivity of small cities and close intercity gaps.