Tuesday, January 13, 2015

Professor Risch - Challenges Conventional Wisdom That Citing More Prior Art Makes for a Better Patent

In Citing References at the PTO (2012), Professor Dennis Crouch tells "as part of the application process, patent applicants have a duty to identify prior art references that are material to patentability."

Citing prior art references is not legally required in the USPTO, but nearly all applicants submit prior art references, and not submitting prior art references is a risky way to save money. As Professor Crouch notes only 13% of applicants submit no prior references January - October 2012. Thus, just ~ 1 out 10 were willing to travel this "brave" road and I doubt things have changed. And it appears to be a brave road indeed as these "no disclosure" patents may end up in litigation. It's true wonder if any survive.

Professor Crouch notes the average of 36 references is skewed by the fact about 10% of patents together cited millions of prior art references. The median is eight prior art references. Of course, those with great resources can implement the conventional wisdom that a patent will less vulnerable to an invalidity attack by submitting more prior art references.

Despite all of this, we now have an article with findings that challenge the conventional wisdom of "gold-plating" patents by submitting lots of prior art. Professor Michael Risch's A Generation of Patent Litigation: Outcomes and Patent Quality(2015) is an interesting study, and in particular challenges the convention wisdom that citing more references at the PTO will result in a better US patent. See finding 3 in the Abstract below.

Here is Professor Risch's abstract:

"This study compares twenty-five years of litigation and patents of the ten most litigious NPEs (as of 2009) with a random group of cases and patents in the same yearly proportions. All cases involving every patent was gathered, allowing the life cycle of each asserted patent to be studied. The data includes litigation data, patent data, reexaminations, and other relevant data. This paper considers outcomes and patent quality. A future paper will examine innovation and markets.

Unsurprisingly, the data shows that the studied NPE patents were found invalid and noninfringed about twice as often as the comparable nonNPEs. But there is more to the story. First, summary judgment challenges were denied at about the same rate. Second, most cases never tested the patent at all: the invalidations were bunched into 3% of the cases. Third, about 17% of the NPE cases involved a patent that was later invalidated, as compared to 3% for the nonNPEs. This left 75% of NPE cases with patents that were never tested and did not involve a patent invalidated at any time (as compared to 90% of nonNPE cases). Thus, one’s view of the data will depend on views about motivations in asserting patents that wind up invalid later and the merits of settlements. The paper presents data about settlements, consent judgments, defaults, and the like, but ultimately takes no position on the quality of untested patents.

Other major findings include:

1. NPE cases are shorter duration than nonNPE cases, even though they are transferred and consolidated more often. Even with transferred cases, NPE cases are shorter.

2. A patent’s likelihood of being invalidated has almost nothing to do with objectively observable patent metrics – including reexamination data. Instead, the odds of invalidation are driven by those cases that are more likely to have a challenge, like the number of defendants or number of patents in the case. Once variables that indicate challenges are considered, a party's status as NPE added no explanatory power.

3. One patent metric was statistically significant in predicting invalidation: backward citations, or the number of prior patents that a patent refers to. But the sign was surprising: the more citations in the patent, the more likely it was found invalid. This may mean that backward citations are another selection variable – patents citing many other patents may be more likely to be highly controversial and thus challenged. This finding implies, however, that “gold plating” patents may not be as beneficial as first thought."

Thus, Professor Risch's findings suggest that the recent practice of citing massive amounts of  prior art during the prosecution of a patent application to make it less vulnerable to an invalidity challenge may have an opposite effect, that is, too much "gold plating" can sink a patent!

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