One feature of the European patent system that is heavily criticized nowadays is related to its complex fragmentation and the induced cost burden for applicants. Once a patent is granted by the EPO, the assignee must validate (and often translate) it and pay the renewal fees to keep it in force...

This paper develops a two-industry model of R&D. A monopolist supplier sells an intermediate good to an oligopolistic buyer industry where firms compete in quantity and quality-enhancing R&D. The supplier can contribute to downstream product improvements by creating spillover knowledge which...