Measuring the private returns to R&D requires knowledge of its private depreciation or obsolescence rate, which is inherently variable and responds to competitive pressure. Nevertheless, most of the previous literature has used a constant depreciation rate to construct R&D capital stocks and...

The contribution made by innovation and new technologies to economic growth and welfare is largely determined by the rate and manner by which innovations diffuse throughout the relevant population, but this topic has been a somewhat neglected one in the economics of innovation. This chapter,...

Recent research on financial market valuation of the knowledge assets of publicly traded firms is surveyed. The motivation for using a market value equation to price knowledge assets is discussed and the theory behind this equation is briefly presented. Then the empirical literature that relates...

The identification of age, cohort (vintage), and period (year) effects in a panel of individuals or other units is an old problem in the social sciences, but one that has not been much studied in the context of measuring researcher productivity. In the context of a semi-parametric model of...

We study the production of knowledge when many researchers or inventors are involved, in a setting where tensions can arise between individual public and private contributions. We first show that without some kind of coordination, production of the public knowledge good (science or research...

The contribution of new technology to economic growth can only be realized when and if the new technology is widely diffused and used. Diffusion itself results from a series of individual decisions to begin using the new technology, decisions which are often the result of a comparison of the...

This paper is a first step toward closing the analytical gap in the extensive literature on the results of interactions between public and private R&D expenditures, and their joint effects on the economy. Econometric studies in this area report a plethora of sometimes confusing and frequently...

Is public R&D spending complementary and thus "additional" to private R&D spending, or does it substitute for and tend to "crowd out" private R&D? Conflicting answers are given to this question. We survey the body of available economectric evidence accumulated over the past 35 years. A framework...

It is known that innovations in the market value of manufacturing firms and their RhD expenditures are related (Pakes (1985) and Mairesse and Siu (1984)). This could be due to shifts in the demand for the output of a particular firm, to shifts in the technological opportunities available to the...

This paper extends earlier work on the R&D to patents relationship (Pakes-Griliches 1980, and Hausman, Hall, and Griliches, 1984) to a larger but shorter panel of firms. Using both non-linear least squares and Poisson type models to treat the problem of discreteness in the dependent variable the...