Patent Quality and Settlement among Repeat Patent Litigants

Abstract

Repeat plaintiffs - those who sue eight or more times on the same patents - have a disproportionate effect on the system. They are responsible for a sizeable fraction of all lawsuits. Their patents should be among the strongest, according to all economic measures of quality. And logic suggests that repeat plaintiffs should be risk averse, settling more of their cases and taking only the very best to trial to avoid having their patents invalidated. In this paper, we test those hypotheses. We find that repeat plaintiffs are somewhat more likely to settle their cases. But, to our surprise, we find that when they do go to trial or judgment, overwhelmingly they lose. This result seems to be driven by two parallel findings: both software patents and patents owned by non-practicing entities (so-called patent trolls) fare extremely poorly in court. We offer some possible explanations for why a group of apparently weak patents nonetheless have so much influence over the system, and some preliminary thoughts about how these findings should shape the reform debate.