We conduct a comprehensive study of all patent trials over the past eleven years. We find that juries are more favorable to patentees than judges, that (to our surprise) the length of a trial has no effect on its outcome, and that there are surprisingly modest differences between patentee win...

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....

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...

Patent law is crucial to encourage technological innovation. But as the patent system currently stands, diverse industries from pharmaceuticals to software to semiconductors are all governed by the same rules even though they innovate very differently. The result is a crisis in the patent...

Economists often assume that a patent gives its owner a well-defined legal right to exclude others from practicing the invention described in the patent. In practice, however, the rights afforded to patent holders are highly uncertain. Under patent law, a patent is no guarantee of exclusion but...