Repeat patent plaintiffs - those who sue eight or more times on the same patents - have a disproportionate effect on the patent system. They are responsible for a sizeable fraction of all patent lawsuits. Their patents should be among the strongest, according to all economic measures of patent...

Sixteen years ago, two of us published the first detailed empirical look at patent litigation. In this Article, we update and expand the earlier study with a new hand-coded data set. We evaluate all substantive decisions rendered by any court in every patent case filed in 2008 and 2009 —...

We test empirically whether purchased patents that are litigated fare better or worse than litigated patents that aren’t purchased. We identified every case filed in 2009 and 2010 that had a definitive winner and had information on the presence or absence of an assignment or other transfer....

Pharmaceutical patents listed in the FDA’s “Orange Book” are some of the most valuable patents in the world. Accordingly, for this valuable subset of patents, it is paramount that the Patent & Trademark Office (PTO) correctly issue valid patents and preclude invalid patents from issuing....