Uncertainty, Patent Length and Firm R&D: a Comment

In a recent paper, Goel (1996) analyses the effect of patent length on firm’s R&D in a model where the timing of innovations is stochastic. He concludes that: ‘Higher patent length does not necessarily lead to more R&D spending’ (1996, p. 77). More precisely, ‘in projects with high probabilities of innovation success firms might actually reduce their R&D spending when the patent length increases’ (1996, p. 78). This conclusion, however, is flawed. The purpose of this note is to correct Goel's analysis, showing that in his model an increase in patent's length unambiguously leads to higher R&D investment. 1