Deriving Empirical Definitions of Spatial Labor Markets: The Roles of Competing Versus Complementary Growth
利用美国中西部八个县1969-1994年的数据，研究发现本地人口增长不仅受本县经济增长影响，还受邻近县及更远距离县经济增长的正向影响，但效应随距离递减，超过三个县半径后转为负向。
If economic growth elsewhere raises an individual’s earning prospects relative to his present location, then the individual will move. However, if the individual can exploit economic growth elsewhere by commuting, he will not need to move to gain from the expansion. County‐level data from eight states in the Midwest over the period 1969–1994 are used to show that local county population responds positively to own‐county economic growth, economic growth in the adjacent county, and economic growth two counties away. The magnitude of the effect decreases as distance from the county increases, and turns negative beyond a three county radius.