The Agglomeration of U.S. Ethnic Inventors

The spatial concentration of ethnic inventors increased significantly from 1995 to 2004, especially in high-tech sectors like computer-related patenting.

The ethnic composition of U.S. inventors is undergoing a significant transformation. While the foreign-born account for just over 10 percent of the U.S. working population, they represent 25 percent of the U.S. science and engineering (SE) workforce and nearly 50 percent of those with doctorates. The spatial distribution of ethnic inventors across U.S. cities is neither uniform nor random, though. Instead, there is agglomeration -- that is, clustering in a defined area -- which reflects the general tendency of both high-skilled and low-skilled immigrants to concentrate in certain U.S. cities. The larger cities often are favored for their greater opportunities for assimilation, but geographical distances of cities to home countries and past immigration networks also are important.

In The Agglomeration of U.S. Ethnic Inventors (NBER Working Paper No. 15501), author William Kerr contributes to our understanding of agglomeration and its relationship to innovation by documenting patterns in the city-level agglomeration of ethnic inventors within the United States. He applies an ethnic-name database to individual U.S. patent records in order to explore these trends in greater detail.

Kerr finds that ethnic inventors have higher levels of spatial concentration than their non-ethnic counterparts throughout the thirty-year period that he studies. Moreover, he observes that the spatial concentration of ethnic inventors increased significantly from 1995 to 2004, especially in high-tech sectors like computer-related patenting. The combination of greater ethnic shares and increasing agglomeration of ethnic inventors has helped to reverse the 1975-94 declines in the overall concentration of U.S. invention. These trends are confined to industrial patents, though; universities and government bodies that are constrained from agglomerating do not show recent increases in spatial clustering.

Kerr describes the ethnic composition of U.S. inventors for 1975-2004. He groups granted patents by application years. The trends demonstrate a growing ethnic contribution to U.S. technology development, especially among Chinese and Indian scientists. Ethnic inventors are more concentrated in high-tech industries, like computers and pharmaceuticals, and in gateway cities relatively closer to their home countries -- for example, Chinese in San Francisco, Europeans in New York, and Hispanics in Miami.

-- Lester Picker