We study how to reward innovators who build on one another. Rewards come in the form of patents. Because patent rights are scarce, the optimal allocation involves sharing: More than one innovator's patent is in force at a given time. We interpret such allocations as patents that infringe one...

In this article, we propose a recursive equilibrium algorithm for the numerical simulation of nonoptimal dynamic economies. This algorithm builds upon a convergent operator over an expanded set of state variables. The fixed point of this operator defines the set of all Markovian equilibria. We...