TY - THES AB - This thesis models a patent race with a differential game approach. Firms strategically invest in R&D and produce knowledge in order to innovate. Whether knowledge is substitutable to the existing knowledge pool affects firm’s incentives to invest in R&D. After innovating successfully, the innovator patents on its techniques so that their opponents cannot infringe. However, a patent system indirectly ensures the monopoly power of the innovator in a product market, which reduces the social welfare. The endogenous benefit of a patent holder is evaluated and an optimal patent policy is suggested in order to balance out the loss of the social welfare and innovation incentives. Besides, the production process usually contains several techniques with different patents and this collection forms a patent portfolio. A model of a patent portfolio race explains why some innovation such as an open-source software without patenting can also be as successful as a private software product. DA - 2016 LA - eng PY - 2016 TI - R&D, patents and innovation: a differential game approach UR - https://nbn-resolving.org/urn:nbn:de:hbz:361-29029585 Y2 - 2024-11-23T12:11:21 ER -