Patent thickets, defensive patenting, and induced R&D: an empirical analysis of the costs and potential benefits of fragmentation in patent ownership

摘要

Patent thickets are sets of overlapping intellectual property rights that occur in fragmented technology markets. Their potential impacts on innovation have become an increasing concern in recent years. I estimate the direct and indirect effects of patent thickets on market value of publicly traded manufacturing firms. I find that patent thickets decrease the market value of firms, holding R&D and patenting activities of these firms constant. I also find that while firms do not change their R&D activities in response to patent thickets, they do reduce negative cost effects of patent thickets on market value through defensive patenting.