After the Supreme Court’s decision in Wal-Mart v. Dukes, 131 S. Ct. 2541 (2011), the application of Daubert at the class certification stage has been one of recent confusion.  Although not all circuits have addressed whether a full Daubert analysis is necessary at the class certification stage, the Eighth Circuit announced its approach in In re Zurn Pex Plumbing Products Liability Litigation, 644 F.3d 604 (8th Cir. 2011), specifically rejecting the need for a full Daubert inquiry when determining issues related to class certification.  Instead, the Eighth Circuit determined that when deciding whether to certify a class under Rule 23, a district court need only examine the reliability of the expert opinions with respect to the preliminary issues at hand—not whether the expert opinions would ultimately be admissible at trial.

In Zurn, homeowners brought a products liability action against manufacturer-defendants, asserting consumer protection, warranty, and negligence claims.  After completing the first portion of the parties’ bifurcated discovery, plaintiffs moved for class certification.  In response, defendants moved to strike the testimony of the expert reports submitted in support of plaintiffs’ motion.  The district court denied defendants’ motion to strike and partially granted plaintiffs’ certification motion.  The Eighth Circuit affirmed on appeal.

In arguing defendants’ motion to strike, the parties disagreed on the appropriate application of Daubert at the class certification stage.  Defendants pointed to American Honda Motor Company, Inc. v. Allen, 600 F.3d 813 (7th Cir. 2010) in arguing that the district court should have determined whether plaintiffs’ expert evidence would ultimately be admissible at trial.  The Eighth Circuit disagreed.  In Zurn, the court found that the district court had appropriately conducted a focused Daubert inquiry to assess whether the expert opinions, based on the experts’ area of expertise and the reliability of their analyses of the available evidence, should be considered in deciding the issues relating to class certification.  The district court properly declined to engage in a full Daubert analysis to assess the admissibility of the expert evidence at trial.  Such an approach, the Eighth Circuit reasoned, was consistent with prior precedent.

In a footnote, the Eighth Circuit rejected the notion that the Supreme Court’s recent decision in Wal-Mart demanded a different result.  Zurn reasoned that a full Daubert analysis would be premature, as subsequent discovery could have an impact on the admissibility of the experts’ analyses down the road.  The preliminary nature of class certification rulings further supported this view.  Additionally, the Eighth Circuit reasoned that the main purpose of Daubert—to protect juries from being swayed by dubious scientific testimony—was not implicated when a judge was faced with determining preliminary issues of commonality, predominance, and superiority.

In light of a Circuit split on this issue, it may be an issue that the Supreme Court ultimately may have to decide.