Innovation beyond Patents: Technological Complexity as a Protection against Imitation

A large portion of innovators do not patent their inventions. This is a relative puzzle since innovators are often perceived to be at the mercy of imitators in the absence of legal protection. In practice, innovators however invest actively in making their products technologically hard to reverse engineer. We consider the dynamics of imitation and investment in technological complexity, both by the innovator and by imitators. We show it can justify high level of proÖts beyond patents, can shed light on the regulation of reverse engineering and can explain delays in adoption of innovations.