We investigate whether patents that are jointly held by legally independent companies help sustain product-market collusion. We use a simple model of repeated interactions to show that joint patents can serve collusive purposes. Our model generates two testable predictions: when joint patents...

This paper assesses the impact of adopting a post-grant review institution in the US patent system by comparing the 'opposition careers' of European Patent Office (EPO) equivalents of litigated US patents to those of a control group of EPO patents. We demonstrate several novel methods of...