A Note on the Spatial Correlation Structure of County‐Level Growth in the U.S.
研究了1984-1994年美国县级人口、就业、收入和收入增长的空间相关性，发现跨县相互依赖仅限于约200英里内，且40英里内相关性下降缓慢，之后加速下降。
This paper examines the spatial correlation structure of county‐level growth across the contiguous United States. Estimated spatial correlograms using data on four different measures of aggregate economic activity—population, employment, income, and earnings—over the period 1984–1994 indicate that cross‐county interdependence is limited to relatively short ranges of distance. For each of the measures, the average correlation between the growth rates of two counties approaches zero within a range of approximately 200 miles. Moreover, the rate at which correlations decline with distance is not uniform. Inside of roughly 40 miles correlations show only a very slow rate of decline whereas beyond this range they drop off at a substantially higher rate.