Professor Sean Tu Publishes Two Articles in the Latest Issue of IP Litigator

West Virginia University College of Law professor Sean Tu published two new articles in the latest issue of IP Litigator. In the September/October 2021 issue, Professor Tu's authored "Characteristics of Patent Examiners Who Issue Litigated / Invalidated Patents" and "Fast versus Slow Examination: How Examiners Use Allowances or Rejections to Delay or Compact Patent Prosecution".

From the abstract of "Characteristics of Patent Examiners Who Issue Litigated / Invalidated Patents":

In a set of two studies , I determine: (1) which examiners are sending patents to litigation and, of those, (2) which examiners are sending invalidated patents to litigation. Together, these studies determine what conditions might predict the likelihood of an examiner’s patents getting litigated or invalidated. Somewhat surprisingly, just because an examiner issues a higher percentage of patents does not mean he will have a similarly higher percentage of invalidated patents.

From the abstract of "Fast versus Slow Examination: How Examiners Use Allowances or Rejections to Delay or Compact Patent Prosecution":

Previous studies have shown that an applicant’s ability to obtain a patent is inexorably linked to the random assignment of a patent examiner. However, not all patent examiners are created equal. Some patent examiners allow patent applications quickly within just one or two Office Actions, resulting in only a few months of substantive patent prosecution. In contrast, other patent examiners constantly reject patents applications, which can result in unnecessarily delaying prosecution and years of substantive patent prosecution. In a set of two new studies, I focus on how different examiners are using different types of rejections to prolong or compact prosecution.

Differences in prosecution times between high and low volume examiners are significant. Specifically, high volume, average volume, and low volume examiners issued a patent in approximately 1.64 years, 3.07 years, and 5.85 years, respectively. Thus, high volume examiners issue patents almost twice as quickly as average volume examiners and more than three times as fast as low volume examiners. This large difference can represent a huge investment in both capital and time for the applicant, as well as for the PTO. However, commentators have not reviewed how examiners are able to have this wide range of issue times while still maintaining their production goals.

I find that slow examiners reject applications based mainly on obviousness, issuing over four times as many obviousness rejections per Office Action as compared to high volume examiners. Furthermore, slow examiners issue five times as many Section 102(a), (g), or (e) rejections and two times as many Section 102(b) rejections. And applicants most commonly make a “missing element” argument to traverse a slow examiner’s Section 102(a), (g) or (e) rejection at three times the rate of a fast examiner. This type of traversal strategy relies on the examiner’s misunderstanding of either the art or the claimed invention. Similarly, applicants also use the “missing elements” argument to traverse a slow examiner’s Section 103 rejection at five times the rate of a fast examiner. Finally, applicants are also three times more likely to use a “teaching away” or “unexpected results” argument to traverse a slow examiner compared to a fast examiner. Both of these arguments can again rely on either the examiner’s misunderstanding of the prior art or a misunderstanding of the claimed invention. In contrast, I find that fast examiners mainly rely on obviousness-type double patenting (ODP) rejections as well as 35 USC 112, 2nd indefiniteness rejections. Applicants overwhelmingly respond to ODP rejections by filing terminal disclaimers and respond to indefiniteness rejections by filing claim amendments.

This study demonstrates that different types of examiners use different strategies to maximize their “counts.” Specifically, slow examiners will generally reject applications, creating lengthy prosecution histories and forcing the applicant to narrow claims, while showing a misunderstanding of either the prior art and/or the claimed invention. In contrast, fast examiners will usually only make one or two rejections that are easily traversed by the applicant before allowing the case, thus creating a small prosecution history with only small amendments to the claims. These two different count maximization strategies lead to significantly different prosecution durations.

Find more of Professor Tu's scholarship on SSRN.