URBAN CLUSTERS AS GROWTH FOCI*
研究了城市集群对人口增长的影响，发现低密度集群中增长为正，高密度集群中为负，对城市规划和区域发展有参考价值。
ABSTRACT Urban clusters are geographic concentrations of urban places, some of which may include major cities. Unlike agglomerations, whose geographic boundaries are clearly delineated, urban clusters have “variable” boundaries, with each urban settlement being part of its “own” cluster of populated places, located within its commuting range. As our study indicates, the effect of clustering on urban growth is not uniform: it appears to be positive in low density clusters, and negative in densely populated ones. In particular, outside densely populated areas, towns surrounded by other localities tend to evince higher rates of population growth than their “lone” counterparts.