The Spatial Component of the Post-Industrial Society
研究了1970年代美国经济核心与外围在产业结构专业化与多样化上的差异，发现外围地区因服务业增长而更趋多样化，核心地区则更专业化，形成了无法用单一部门描述的后工业经济。
The growth and decentralization of the American economy during the 1970s was accompanied by an increasing divergence in structure between core and periphery as to the degree to which either was specialized or diversified. A diversified economy was defined as one in which the relationship that exists between the sizes of its sectors is closer to equality than what is true for a specialized one. When this concept was applied to income data for 183 B.E.A. economic areas, it was found that there was a relationship between growth and the degree to which each area was diversified in 1978, and that the strength of the relationship had increased since 1971. The high growth periphery was becoming more diversified while the low growth core was becoming more specialized. Increasing peripheral diversification was attributed to a better response to a more diversified national demand for its goods and services, especially in the tertiary sector. In addition, nowhere was manufacturing developing into the large, integrated industrial complexes so typical of the core. The result was the development of a post-industrial economy that had acquired a degree of diversity in its structure such that it could no longer be described with a sector name.