中国的三大都市圈：辐射范围及差异

本文从新经济地理学中的“中心一外围”理论出发，利用中国城市级面板数据，以港口城市上海、香港、天津为中心的三大都市圈为研究对象，考察了城市在都市国内的地理区位与该城市人均GDP的关系。研究发现，珠三角与长三角都市圈内的城市经济发展水平与到大港口距离间存在“一型”的三次曲线关系。在到大港口的一定距离范围内，集聚力超过离散力，距离核心城市越远，人均GDP越低，但当距离远到一定程度时，离散力就越来越强，出现人均GDP的第二个局部高点。因此，“一型”曲线的第一个谷底点以内的区域就可以作为都市圈的辐射范围，而曲线第一段地理与人均GDP的负相关系数则可以作为核心城市的相对集聚力的度量。本文的主要发现是，长三角都市圈核心城市上海的辐射范围和集聚特性要稍强于珠三角都市圈，而环渤海湾都市圈暂时仍然是多个港口城市共同起到辐射作用的城市体系。

China's City Clusters:Their Different Scopes

Based on the ＂core-periphery＂ theory of New Economic Geography, this paper studies the three major city clusters centering respectively around three large ports, Shanghai, Hong Kong and Tianjin, using Chinese city-level panel data. We find that the relationship between a city＇ s GDP per capita and its distance to the nearest port shows a cubic curve of ＂~＂＂ shape in Pearl River Delta （PRD） and Yangtze River Delta （YRD）. Within a certain distance from a major port the farther away from the core city, the lower a city＇ dispersion effect gets stronger. Thus, the first bottom when agglomeration effect dominates dispersion effect, s GDP per capita is. But as the distance is farther, the of the ＂~＂ shape can be interpreted as the scope of the city cluster, and the slope of the first section of the curve with dispersion effect of the core city. A major finding is reflects the relative agglomeration effect, compared that YRD＇ s relative agglomeration effect is slightly stronger than that of PRD. Whilst city clusters around Bohai Sea remain as a city system where several port cities present agglomeration effects all together.