Understanding the Realities of Modern Patent Litigation

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-decisions made between 2009 and 2013. We consider not just patent validity but also infringement and unenforceability. Moreover, we relate the outcomes of those cases to a host of variables, including variables related to the parties, the patents, and the courts in which those cases were litigated. The result is a comprehensive picture of the outcomes of modern patent litigation, one that confirms conventional wisdom in some respects but upends it in others. In particular, we find 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.Sixteen years ago, two of us published the first detailed empirical look at patent litigation.2 That study provided a wealth of valuable information about patent-validity litigation, including the discovery that nearly half of all patents litigated to judgment were held invalid.3 But it was also limited in various respects. The study was based only on patent-validity decisions that finally resolved the case on the merits and only on reported decisions available in a particular legal reporter.4 The latter limitation meant that almost half of the decisions were appellate.5 Importantly, the cases serving as the study's data sources are now on average more than twenty years old.6In 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-decisions made between 2009 and 2013. We consider not just patent validity but also infringement and unenforceability. Moreover, we relate the outcomes of those cases to a host of variables, including variables related to the parties, the patents, and the court in which the case was litigated. The result is a comprehensive picture of the outcomes of modern patent litigation, one that confirms conventional wisdom in some respects but upends it in others.In Part I, we discuss previous efforts to evaluate patent litigation empirically. In Part II, we discuss our methodology and the choices we made in study design. We present our results in Part III.I. The Prior Art: Efforts to Understand Patent Litigation So FarA number of scholars have empirically studied specific patent law doctrines. Claim construction is the most common, with most articles focusing on appellate cases.7 Obviousness has also been a point of scholarly interest,8 as have inequitable conduct9 and the doctrine of equivalents.10 Although the empirical research into patent litigation just mentioned has largely focused on Federal Circuit decisions,11 with research employing data from district court litigation typically having been limited to opinions available on Westlaw or Lexis,12 there have been a few notable exceptions.13 Unreported decisions, especially denials of summary judgment and the results of jury trials, are lacking from these data sets.14Recently, the underlying documents, including motions and opinions, from district court litigation became more readily available. Electronic filing requirements meant that the online filing tool, Public Access to Court Electronic Records (PACER), has a nearly complete collection of litigation documents from patent cases.15 Some scholars have taken advantage of PACER data to analyze district court decisions.16 But the raw data provided by the Administrative Office of the United States Courts is notoriously error-prone,17 and it does a poor job of classifying outcomes.18II. Our MethodologyIn this Part, we explain in detail the techniques we used to locate and collect the data. …