Admissibility versus Sufficiency: Controlling the Quality of Expert Witness Testimony in the United States
44 Pages Posted: 6 Mar 2012 Last revised: 23 Jan 2014
Date Written: March 5, 2012
Daubert v. Merrell Dow Pharmaceuticals, established a new method of assessing the admissibility of expert testimony in federal courts. The opinion and two subsequent opinions,General Electric v. Joiner and Kumho Tire v. Carmichael, have had a profound impact on civil litigation in the United States. Parties now routinely challenge the admissibility of the opposing expert’s testimony. This has lead to the exclusion of experts in hundreds, perhaps thousands of cases. Given this substantial impact, it is perhaps surprising that considerable confusion still persists concerning exactly how trial courts should think about the decision to admit or exclude expert testimony. In this paper, we argue that much of the confusion exists because of the four factors provided in Daubert for assessing the reliability of an expert’s methodology. Reading lower court cases that address admissibility reveals that those factors are largely unhelpful in resolving the admissibility question. Rather than conceiving of the issue as one involving admissibility, we argue that the best way to clarify the Daubert inquiry is to appreciate that most admissibility decisions are best thought of as sufficiency judgements. By that, we mean that the court should consider the scientific evidence proffered by the expert and engage in what courts have long done–assess the sufficiency of that evidence to permit the fact finder to reasonably infer causation (or whatever other issue the expert’s opinion addresses). Courts have, since the advent of juries, made the determination of whether a party’s evidence is sufficient for an inference or would, on the other hand, only leave the jury to impermissible speculation about the issue in dispute. We not only believe this is a better approach, we also believe that a close reading of opinions indicates that in fact many courts do adopt a sufficiency approach when making Daubert admissibility rulings.
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