In recent years, large concentrations of employment have developed outside of traditional urban  cores and central business districts.  Our research focuses on analyzing the changing distribution  of employment in metropolitan areas by expanding on the idea of “edge cities” (Garreau 1991),  wherein employment has moved to the urban fringe.  Our approach uses tract -to-tract commuting  data from Census 2000 to identify high-employment nodes within metropolitan areas.  We first identify high- employment census tracts by comparing the number of jobs to the number of  residents in each tract and then delineate clusters of contiguous high-employment tracts based on  the density of jobs in these areas.  We then compare outlying employment clusters with  traditional central business districts and contrast employment clusters of varying job densities.   Our method has several advantages over existing methods of identifying employment clusters:  It  is conceptually simple, can use publicly available data, relies on a st andardized unit of geography  that is applicable across the entire United States, and offers the ability to examine data from  multiple census years