Locational Differences in Inventive Effort and Their Determinants

Wilbur R. Thompson, The Rate and Direction of Inventive Activity: Economic and Social Factors (Princeton University Press, 1962), https://www.nber.org/books-and-chapters/rate-and-direction-inventive-activity-economic-and-social-factors/locational-differences-inventive-effort-and-their-determinants.