Licensing in a patent thicket allows firms to either avoid or resolve hold-up. Firms' R&D incentives depend on whether they license ex ante or ex post. We develop a model of a patent portfolio race, which allows for endogenous R&D efforts, to study firms' choice between ex ante and ex post...

This paper draws attention to two important characteristics of knowledge which so far have been left unexplored, and proposes a new method to capture them in economic modeling with the help of vectors. The direction of the vector represents the knowledge's complementarity with other knowledge...

This paper builds a model in which clustering emerges as the equilibrium outcome driven by informational imperfections and the importance of knowledge and uncertainty in innovative production even when knowledge is fully exclusive and appropriable. This motive for clustering will be stronger the...