Strategic Patenting and Software Innovation

Abstract

Strategic patenting is widely believed to raise the costs of innovating,especially in industries characterised by cumulative innovation. This paperstudies the effects of strategic patenting on R&D, patenting and marketvalue in the computer software industry. We focus on two key aspects:patent portfolio size which affects bargaining power in patent disputes, andthe fragmentation of patent rights (.patent thickets.) which increases thetransaction costs of enforcement. We develop a model that incorporates botheffects, together with R&D spillovers. Using panel data for the period 1980-99, we find evidence that both strategic patenting and R&D spilloversstrongly affect innovation and market value of software firms.patents, anti-commons, patent thickets, R&D spillovers, marketvalue