Does the Presumption of Validity Matter? An Experimental Assessment

47 Pages Posted: 11 Nov 2014 Last revised: 4 Aug 2015

See all articles by Jeremy Bock

Jeremy Bock

Tulane University Law School

Date Written: December 10, 2014


Few doctrines in patent law are perceived to be as important as the presumption of validity. Despite its perceived importance, the impact of informing the jury of the presumption has not been examined empirically, but rather has remained the province of assumptions and speculation.

Because the presumption is, at bottom, a procedural device that assigns the burden of proof, the Federal Circuit has held that it need not be included in the jury instructions so long as the jury is informed of the clear and convincing standard for proving invalidity. Underlying this holding is the assumption that the presence or absence of the presumption instruction would not materially affect the jury’s decision-making on invalidity issues. But litigants often view the presumption not simply as a procedural device, but also as a mechanism for influencing the jury with potentially outcome-determinative effects. This mismatch in perception between the Federal Circuit and litigants regarding the impact of the presumption instruction has gone largely unnoticed and unexamined. This Article reports the first experimental study on the impact of instructing the jury on the presumption of validity. The data reveal statistically significant differences in the rate of invalidation depending on whether the mock jurors were informed of the presumption. Based on this finding, the Article analyzes the selection of a validity baseline in light of both procedural considerations and error costs.

Keywords: patent, litigation, empirical, survey, experiment, invalidity, obviousness, PTO, presumptions, procedure, error costs

Suggested Citation

Bock, Jeremy, Does the Presumption of Validity Matter? An Experimental Assessment (December 10, 2014). 49 U. Rich. L. Rev. 417 (2015), University of Memphis Legal Studies Research Paper No. 145, Available at SSRN:

Jeremy Bock (Contact Author)

Tulane University Law School ( email )

6329 Freret Street
New Orleans, LA 70118
United States

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