We consider the effects of product and process patents on profits and welfare. In a duopoly model, we show that if the cost of imitation is not very large, prisoner's dilemma occurs under process patent, thus creating lower profit of each firm under process patent than under product patent....

type="main" <p>We show the effects of entry of a new firm on the profits and welfare when the firms share the same initial cost of production but differ in terms of the costs of undertaking R&D. Considering a Cournot oligopoly model with innovation and linear demand and production costs, we show...</p>