Understanding the Realities of Modern Patent Litigation, by John Allison (Texas), Mark Lemley (Stanford), and David Schwartz (Chicago-Kent), supplies a "comprehensive picture of the outcomes of modern patent litigation." The paper updates and expands upon prior work by coding "all substantive decisions rendered by any court in every patent case filed in 2008 and 2009 -- decisions made between 2009 and 2013." The study evaluates patent validity as well as infringement and unenforceability claims. Interestingly, the paper notes "a surprising amount of continuity in the basic outcomes of patent lawsuits over the past twenty years, despite rather dramatic changes in who brought patent suits during that time."
While the data only include litigation filed in 2008 and 2009 and the analyses only involve cases that persisted to the dispositive motion or trial stages (most lawsuits settle before this), the paper will certainly interest those seeking an empirical footing in patent litigation.