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The Supreme Court’s trilogy of evidence cases, Daubert, Joiner, and Kumho Tire appear to mark a significant departure in the way scientific and expert evidence is handled in federal court. By focusing on the underlying methods used to generate the experts’ conclusions, Daubert has the potential to impose a more rigorous standard on experts. Given this potential, some individuals have called for states to adopt the Daubert standards to purge “junk science” from state courts. However, there is relatively little empirical support for the notion that Daubert affects the quality of expert evidence. Using a large dataset of state court litigation, we examine whether state adoption of the Daubert standards has a systematic effect on the observable characteristics of experts retained in civil cases. We find very little evidence in support of a significant Daubert effect. This is true even when we do a more detailed analysis of experts in products liability cases, an area of particular concern in the expert evidence debate. These results suggest that, at the state level at least, adoption of the Daubert standards has not led to increasing rigor in expert testimony.


Scientific and expert evidence, federal courts, state courts, standards of admissibility, quality of expert testimony, products liability, judges

Publication Title

Supreme Court Economic Review

Publication Citation

20 Sup. Ct. Econ. Rev. (2012)