I introduce patents into a general equilibrium model of innovation, where innovators choose between creating a new product market and competing in an existing market. Patent holders demand royalties from sequential innovators, but are constrained by the ability of innovators to work around...

I develop a model of monopolistic competition in which I distinguish between niche markets and mass markets, in the spirit of Holmes and Stevens (2013). Firms choose between entering a small niche market with high markups or a large mass market with low markups. Entry costs have a much greater...

I incorporate an insight of Friedrich Hayek - that competition allows a thousand flowers to bloom, and discovers the best among them - into a model of Schumpeterian innovation. Firms face uncertainty about the optimal direction of innovation, so more innovations implies a higher expected value...