Perfectly competitive innovation

Based partially on the belief that innovation is not possible under perfect competition, a huge number of papers have been written about the nature of innovation under monopoly or oligopoly. In fact, competitive rents can and do sustain innovation in the complete absence of monopoly power. However, little is known about the source and significance of these rents, or about the way in which innovative activity takes place under conditions of competition. We begin to remedy this imbalance by examining the way in which competitive innovators earn rents both in theory and in practice. r 2008 Elsevier B.V. All rights reserved.