On March 9, 2011, the Eleventh Circuit took a position in the ongoing debate over just how far District Courts should go in reviewing and evaluating expert evidence when deciding whether to certify a class under Rule 23. In Sher, et al. v. Raytheon Company, No. 09-15798 (11th Cir. March 9, 2011) [link to ruling], the Eleventh Circuit adopted – and arguably even expanded upon – the approach taken by the Seventh Circuit last year in American Honda Motor Co., Inc. v. Allen, 600 F. 3d 813 (7th Cir. 2010) [link to ruling], which held that a District Court is duty-bound to conclusively rule on the admissibility of expert opinion prior to ruling on any class certification motion that relies upon such opinion evidence. Now, as a result of the ruling in Sher, District Courts in the Eleventh Circuit must not only consider the admissibility of such expert evidence, but also its weight in deciding whether a plaintiff has met the burden of proving that there is “enough evidence to support a class[.]” Sher, at 8-9.

In Sher, the named plaintiffs sought certification of a class consisting of all owners of real property allegedly impacted by the release of hazardous waste from a facility operated by Raytheon in St. Petersburg, Florida. In briefing class certification, the named plaintiffs offered the analysis of a groundwater expert and a damages expert to establish: (1) that a toxic underground plume of pollution stretched one mile long and 1.7 miles wide in the groundwater under Raytheon’s facility; and (2) that individual property owners’ damages could be determined by a hedonic multiple regression model, which could measure everyone’s diminution-in-value damages. This model supposedly would replace an individual-by-individual assessment of damages to property (which could mean that individualized issues predominated over common issues, making class certification inappropriate).

The defense offered evidence from its own experts, who challenged both the methodology and conclusions of the reports presented by the named plaintiffs’ experts. The District Court noted that even though the expert reports differed markedly as to the scope of the contamination and its impact on property values, it was acceptable to certify a class without deciding which expert opinions were sound. Undertaking that analysis, the District Court feared, would delve too far into the merits of the named plaintiffs’ case.

The Eleventh Circuit found this was error, because the District Court wrongly “side-stepped” the tough questions of which experts’ opinions had a solid scientific foundation. Instead, the Eleventh Circuit reasoned that the District Court should have weighed conflicting expert testimony presented by both parties. Thus, instead of postponing for another day the battle of the experts, the Eleventh Circuit has now made clear that District Courts must make the hard decisions on expert opinions early, before issuing any rulings on class certification.

Sher has broad application, and will assist employers in opposing motions for class certification in workplace class actions in the Eleventh Circuit.