October 2010

Daubert recognizes that peer review and publication are factors courts may consider in determining the reliability and, hence, admissibility, of expert testimony:

Another pertinent consideration is whether the theory or technique has been subjected to peer review and publication. Publication (which is but one element of peer review) is not a sine qua non of admissibility; it does not necessarily correlate with reliability, and in some instances well-grounded but innovative theories will not have been published. Some propositions, moreover, are too particular, too new, or of too limited interest to be published. But submission to the scrutiny of the scientific community is a component of “good science,” in part because it increases the likelihood that substantive flaws in methodology will be detected. The fact of publication (or lack thereof) in a peer reviewed journal thus will be a relevant, though not dispositive, consideration in assessing the scientific validity of a particular technique or methodology on which an opinion is premised.

But how do these considerations affect the admissibility analysis? Significantly. Experts testifying in large-scale litigation are usually leaders in their field—when the outcome depends upon compelling expert testimony, parties ordinarily retain first-string experts. Challenging the experts’ qualifications will almost always be futile, so focusing on peer review and publication will strengthen any challenge to the testimony.

From the same court (though different panel) that gave us Gass v. Marriott Hotel Servs., Inc., 558 F.3d 419 (6th Cir. 2009)—reversing the Western District of Michigan’s summary judgment for a pest control company after concluding that the plaintiffs did not need expert testimony to get to a jury on their claims that they suffered a complex constellation of symptoms like black tongues and brain fog as a result of exposure to two squirts of benign pesticide—comes one of the most insightful analyses of the admissibility of causation testimony in recent years. In Tamraz v. Lincoln Elec. Co., Nos. 08-4015/4016, Slip op. (6th Cir. Sept. 8, 2010 ), the court, in a 2-1 decision, overturned a $20 million verdict for the plaintiff because the district court erred in admitting the testimony of the plaintiff’s principal expert that the plaintiff suffered a form of Parkinson’s Disease as a result of exposure to manganese in the defendants’ products.