Economists and other scholars studying technical advance have had an easier time getting a handle on “demand-side” factors than on “supply-side” ones. It has proved much more difficult to gain a solid comprehension of factors influencing the “supply” of invention or technical advance. In particular, economists have struggled, and not always effectively, with the proposition that invention proceeds more rapidly and effectively in areas where “technological knowledge” is strong, than in areas where knowledge is weak. The issue here of course is partly empirical, but it is conceptual as well; serious exploration requires a theory, explicit or implicit, that enables the phrase “the strength of knowledge” to take on some concrete meaning. This is the aim of this essay.
