In exchange for the rights provided by a patent, § 112 of the Patent Act requires patentees to clearly explain what their invention is (a requirement known as claim definiteness), as well as how to make and use it (the disclosure requirements of enablement and written description). Many concerns about the modern patent system stem from failures to enforce these requirements adequately. Patents cannot serve as efficient property rights if no one can determine the boundaries of those rights, and disclosure failures can lead to patents that cover far more than was actually invented. Better enforcement of § 112 may be the best way to address the problem of “patent trolls” asserting overbroad and unclear patents. But despite the critical importance of § 112 to the functioning of the patent system, there is surprisingly little empirical data about how it has been applied in practice. For example, although the conventional wisdom is that courts have reached different outcomes when applying § 112 to different technologies and industries, these assertions are based on only a handful of prominent cases.
To remedy this reliance on anecdotes, we have created a hand-coded dataset of 1,144 reported court decisions from 1982 to 2012 in which U.S. district courts or the Court of Appeals for the Federal Circuit rendered a decision on the enablement, written description, or claim definiteness requirements of § 112. We coded validity outcomes under these three doctrines on a novel five-level scale so as to capture significant subtlety in the strength of each decision, and we also classified patents by technology and industry categories. We also coded for a number of litigation characteristics that could arguably influence outcomes. Although one must be cautious about generalizing from reported decisions due to selection effects, our results show some statistically significant disparities in § 112 outcomes for different technologies and industries, although fewer than the conventional wisdom suggests, and not always in the direction that many have believed. Just as importantly, our analysis reveals the effects of other variables on § 112 outcomes, including whether a district court or the Federal Circuit made the last decision in a case, whether a patent claim was drafted in means-plus-function format, and whether a case was decided before or after Markman v. Westview Instruments (holding that interpretation of patent claims is for the court, not the jury).
Patent disclosure and definiteness have been the focus of much recent debate about the patent system. Commentators have argued, for example, that the written description doctrine should be eliminated and that the enablement and definiteness requirements should be significantly revised, and the Supreme Court set forth a new test for indefiniteness in 2014, the contours of which remain uncertain. Our results on how § 112 has been applied in practice will be helpful in evaluating current proposals for reform, and our rich dataset will enable more systematic future studies of these critical doctrines.This draft has already benefited from helpful comments from early readers, and we welcome additional thoughts. Please feel free to email us at the addresses listed at the top of the draft paper. Either John or I will be discussing this work at several upcoming events, including the Northwestern Searle Center Third Annual Research Roundtable on Patents and Technology Standards, PatCon5 at the University of Kansas School of Law, and the American Law & Economics Association Annual Meeting at Columbia Law, and we are looking forward to getting additional feedback at those events.