We investigate incidence and evolution of patent thickets. Our empirical analysis is based on a theoretical model of patenting in complex and discrete technologies. The model captures how competition for patent portfolios and complementarity of patents affect patenting incentives. We show that...

We study the blocking effect of patents on follow-on innovation by others. We posit that follow-on innovation requires freedom to operate (FTO), which firms typically obtain through a license from the patentee holding the original innovation. Where licensing fails, follow-on innovation is...

Complex high technology industries are increasingly affected by patent thickets in which firms' patents mutually block the use of important technologies. Firms facing patent thickets patent intensively to acquire bargaining chips and use licensing to ensure freedom to operate. Such licensing...

This report analyses whether entry of UK enterprises into patenting in a technology area is affected by patent thickets in the technology area.The aim is to contribute to our understanding of the role of patent thickets as a barrier to entry into new technologies for UK enterprises, in...

The aim is to contribute to our understanding of the role of patent thickets as a barrier to entry into new technologies for UK enterprises, in particular small and medium sized enterprises (SMEs).The report consists of several parts:A review of the literature on patent thickets, including the...