This paper uncovers a series of empirical facts regarding the sources of U.S. urban growth in the 1880s. We use a large theoretical literature to provide motivations for a number of potential sources of growth, particularly those based on geographical proximity externalities. These sources are...

This paper evaluates whether the relative concentration of funding for small, research-oriented firms in a small number of high-technology industries is related to differences across industries in the appropriability level facing small firms. We exploit a novel test based on the relationship...

Title from caption. "First draft: 3 March, 1997; this version: 1 September 1997"--P. [1] -- September 1997"--Cover.

The appropriability of innovation depends not only on the instruments available to an innovator to protect private returns, but how those instruments interact with each other as part of the firm's entrepreneurial strategy. We consider the interplay between two appropriability mechanisms...