The coincidence of patent thickets-A comparative analysis

The growth of patent thickets-technology fields that are characterized by a large overlap of rights between different right holders-poses a challenge for innovators. Patent thickets are argued to create strong friction in innovation due to a pronounced potential for holdup. So far, we do not know whether patent thickets coincide in all patent systems or if differences exist that policy makers and managers must take into account when aiming to disentangle and to navigate patent thickets, respectively. To address this gap, we measure patent density of technology fields in the patent systems of the United States, the German patent system governed by the German Patent and Trademark Office (DPMA), and the European patent system governed by the European Patent Office (EPO). Our comparisons reveal both interesting differences and similarities between the analyzed patent systems. Although the United States and the EPO patent system show similar relative patent density patterns across technology fields, the German patent system strongly differs from the previous two. This implies that such deviations need to be taken into account by policy makers when considering regulatory measures as well as by companies in their intellectual property strategy. (C) 2014 Elsevier Ltd. All rights reserved.