Not So Obvious After All: Patent Law's Nonobviousness Requirement, KSR, and the Fear of Hindsight Bias
Before the creation of the Federal Circuit in 1982,
nonobviousness served as the primary gatekeeper for
patents. When patent holders sued for infringement and
lost, more than sixty percent of the time, they lost on the
grounds that their patent was obvious. With the advent of
the Federal Circuit, nonobviousness became a much less
difficult hurdle to surmount. From 1982 until 2005, when
patent holders sued for infringement and lost, obviousness
was the reason in less than fifteen percent of the cases.
While obviousness remained formally a requirement of
patent protection, there can be little doubt that the Federal
Circuit had substantially diminished the doctrine's once
A potential turning point arose in 2007, however, with
the Court's decision in KSR v. Teleflex. In its decision, the
Court, with one hand, rejected some of the key restrictions
the Federal Circuit had placed on the obviousness
doctrine, and with the other, broadened the circumstances
under which obviousness could be found. Taken at face
value, the Court's decision seemed poised to reinvigorate
the nonobviousness requirement. Yet an analysis of
appellate patent decisions since 2007 reveals that the
Court's decision has led to only a slightly increased role
for the doctrine. By any measure, the nonobviousness
requirement remains a pale shadow of its former self.
This Article presents this historical background and
then turns to the fear of hindsight bias that seems to have
motivated much of the desire to limit obviousness's reach.
As articulated by the Federal Circuit, hindsight bias
represents the fear that a judge or jury will use an
inventor's own invention against her. Having been told of
the inventor's solution, the judge or jury will use the
inventor's own actions as a roadmap showing how to
combine existing prior art elements to solve the problem at
hand. With the benefit of hindsight, a judge or jury will
too readily infer that the inventor's solution was obvious.
In a pair of articles, Professor Gregory Mandel has
presented results from empirical tests that he believes
demonstrate the potential for substantial hindsight bias in
patent litigation. In this Article, the authors modify and
extend Professor Mandel's empirical tests. Our results
raise questions regarding Professor Mandel's conclusions
and tend to refute the notion that hindsight bias is a
serious problem in patent litigation
Lunney, Glynn S. Jr. and Johnson, Christian T.
"Not So Obvious After All: Patent Law's Nonobviousness Requirement, KSR, and the Fear of Hindsight Bias,"
Georgia Law Review: Vol. 47:
1, Article 3.
Available at: https://digitalcommons.law.uga.edu/glr/vol47/iss1/3