Hierarchy and concentration in the American urban system of technological advance

This paper investigates aspects of the urban hierarchy and concentration of patent sub-categories in United States metropolitan areas by estimating Zipf, Gini and Moran's I coefficients. Results do not support a power law depiction of the location of disaggregate patenting in the entire metropolitan system. The most concentrated and hierarchical patent technologies are computer hardware and software, computer peripherals, information storage, communications, surgery and medical instruments, nuclear and x-rays, semiconductor devices, optics and organic compounds. Technologies are cross-classified, which reveals aspects of variety in locational patterns and offers clues into systems of knowledge exchange in urban-based technological advance.