"Wal-Mart" Notable for Rulings on Evidetiary Issues

Abstract

Commentary and analysis of the Supreme Court’s June 2011 decision in Wal-Mart Stores, Inc. v. Dukes, with a focus on the Court’s discussion of various evidentiary issues raised during the trial court’s conduct of class certification proceedings. The Wal-Mart litigation, embracing the largest gender-based employment discrimination brought by female Wal-mart employees against the country’s largest employer, garnered extensive media coverage that largely addressed on the underlying merits of the alleged discrimination claims. However, somewhat overlooked in analysis of the Court’ opinion was the majority’s discussion of evidentiary issues implicated in the class certification decision. 

Although the Court’s analysis centered on the failure of the class proponents to satisfy Rule 23(a) threshold commonality requirement, the Court also addressed various issues relating to the offers of proof in support and opposition to the class certification. In particular, the Court addressed the sufficiency of the expert witness testimony of a sociologist proffered by the plaintiffs in support of certification, and opposed by Wal-Mart. Significantly, although the Court did not directly decide the issue, the Court obliquely suggested that Daubert hearings to evaluate the reliability of expert witness testimony might be appropriate at class certification hearings. Hence, the Court left open the question of whether trials courts must exercise their Daubert gatekeeping function as part of class certification proceedings. 

In addition, the Court also addressed issues relating to the use of statistical evidence to support a showing of classwide gender discrimination, as well as the use of anecdotal testimony for the same purpose. In both instance, the Court eschewed the type of evidence proffered by the plaintiffs. Therefore, the Court’s various rulings on evidentiary issues implicated in the Wal-Mart class certification may turn out to be as consequential as the Court’s central ruling on Rule 23(a) commonality requirement.