A simple model of R&D: An extension of the Dorfman-Steiner theorem

Abstract

This paper extends the seminal Dorfman-Steiner (American Economic Review, 44, 826–36, 1954) theorem by putting underlying structures on the determination of market share and on the production of quality or technology. The model developed in this paper yields a demand-pull, technology-push theory of R&D, where the profit-maximizing R&D intensity (i.e., the ratio of R&D expenditure to sales) is determined jointly by consumer characteristics, represented by the elasticities of consumer value with respect to price and quality, and firm-specific technological competence or simply R&D productivity, measured as the R&D elasticity of quality or technological output.