Patently Non-Obvious: Empirical Demonstration that the Hindsight Bias Renders Patent Decisions Irrational

This Article reports an experimental study that provides the first empirical demonstration of the hindsight bias in patent law. The results are dramatic along several fronts: (1) the hindsight bias distorts patent decisions far more than anticipated, and to a greater extent than other legal judgments; (2) jury instructions that explicitly identify and warn against the hindsight bias do not ameliorate its impact; (3) the admission of secondary consideration evidence does not cure the hindsight bias; (4) neither the Federal Circuit’s suggestion test nor the Supreme Court’s Graham requirements appear to resolve the hindsight problem; and (5) the hindsight problem pervades patent law to an extent not previously recognized—it biases decisions under the doctrine of equivalents, claim construction, the on-sale bar, and enablement.