Discussions about patent quality often revolve around concerns that so-called ‘weak’ patents are being (mis)used in litigation to achieve favourable licensing conditions for the benefit of rights holders. The respective risk is allegedly higher under the bifurcation system practised in Germany, where patent infringement and validity are decided by different courts and, due to the typically longer validity process, an injunction could in principle be granted for a patent that is later declared invalid.
The narrative of weak or low-quality patents is mainly based on the outcomes of nullity proceedings. In simple terms, the full and partial invalidation of patents in such proceedings is considered as an indicator (or even evidence) of low-quality assets and a weak system in general. In Germany, focus has been placed on the purportedly high invalidation rates resulting from proceedings before the German Federal Patent Court.
At first glance, the assumption that invalidity rates reflect low patent quality appears plausible. However, a closer look reveals that this assumption mirrors a rather oversimplified and fragmented view of the issue of patent quality. When putting the figures into perspective, the number of patents that are found invalid is in fact quite small.
This article addresses the question of whether invalidity rates are per se a reliable indicator of patent quality, focusing on the German situation. It follows with some general considerations regarding the informative value of invalidity rates in connection with the overall patent landscape. Specific attention is placed on the suitability of partial invalidations as an indicator of low patent quality, with a particular focus on the life expectancy of patents after their partial invalidation.