Do US patent examiners consider applicant-submitted prior art?

What do US patent examiners do with the prior art that is submitted by the applicant?  Under U.S. law, as part of their duty of candour, applicants are obliged to submit any prior art of which at they are aware (although applicants are not under any obligation to carry out a search out for prior art). After all, a US patent examiner seems to have only a limited amount of time to search for, evaluate, and apply the prior art during the entire process of examination. In a 2001 article, Lemley estimated that an examiner devotes only about 18 hours, on the average. Moreover, the submission of prior art by the applicant plays an important role in the strong presumption of validity that a registered patent enjoys under US law. Surely, then, the examiners must be making copious use of the prior art that has been submitted by applicants.

The answer is—maybe not, at least based on a study reported in the respected journal, Research Policy, Christopher Cotropia, Mark Lemley and Bhaven Sampat, “Do applicant patent citations matter?”, 42 (2013), 844-855). (This Kat was not able to find a link to the text of the article, but there is a version of the article that is available for Kat readers on ssrn.com, here.) The authors found, to their surprise”, that “[p]atent examiners generally do not rely on what would appear to be the most promising source of prior art: information submitted by the applicants themselves.”

Stated more comprehensively:

… [P]atent examiners did not use applicant-submitted art in the rejections that narrowed claims before these patents issued, relying almost exclusively on prior art they find themselves. This is not simply because the applicants have “drafted around” the art they submitted. Even late-submitted art is not commonly used by examiners in their rejections. Nor does the examination appear to be that applicant art is uniformly weak. We also provide evidence suggesting examiners are less likely to use prior art discovered by foreign search authorities for the same invention, art that is presumably of better than average quality and relevance.

As such, the authors go on to observe:

“Our findings have potential implications for policy initiatives that aim to improve patent quality through bringing more ‘prior art’ before examiners, under the theory that with better access to prior art they would be less likely to issue patents of questionable validity.”

Regarding the basic finding, namely that examiners rely on the results of their own searches, the study concluded that 98% of applicant-submitted citations of US patents are not used by examiners in rejections. Instead, more than 90% of the US patents that are relied upon by examiners in rejections derive from patent searches carried out by the examiner. Moreover, examiners used only 2.9% of citations of foreign patents submitted by applicants, and even less applicant-submitted non-patent art, namely 1.1%, in rejections.

And so, the question: how do we account for the apparent fact that US examiners are making only very limited use of applicant-submitted prior art; instead, they rely on their own search results. The authors reject the claim that examiners do so because applicant-submitted art is of lower quality. Instead, the authors focus on two possibilities: either the examiners are acting in an efficient, time-saving manner in relying on their own searches, given the time constraints to read and analyse the prior art submitted by the applicants (especially in light of claims that applicants sometimes tend to “flood” the examiner with prior art) or the examiners are evidencing what it is called the “myopia effect”, namely that examiners prefer to rely on the art they find as opposed to what the applicants provide. The authors opt for the second explanation: “[T]here is literature suggesting that people tend to think more highly of things they do themselves than things others provide to them ”, relying on an article by Buccafusco and Sprigman, “Valuing intellectual property: an experiment”, Cornell Law Review 2012.

This Kat appreciates that behavioural economics is all the rage, here, and that the “myopia effect” would seem to fit within this empirical approach to the social sciences. Indeed, the “myopia effect” might explain the basic finding of the study, namely that US examiners do not use the prior art submitted by applicants. But more empirical work is needed. For the moment, the empirical rigour that undergirds the research method of the study does not extend to the explanation for the behaviour observed.Perhaps this will be the subject focus for a further study. Be that as it may, the current research does offer much food for thought on the way that applicant-submitted prior art impacts on the examination process, at least in the US.