In Wal-Mart Stores, Inc. v. Dukes, 564 U.S.338, 131 S.Ct. 2541, 180 L.Ed.2d 374 (2011), a high-profile class action suit, the United States Supreme Court dramatically changed class action law. There seems little doubt that Dukes will profoundly affect class action matters, but the Dukes Court largely declined to address the expert testimony issues that have split the federal circuits, albeit while signaling the Court’s leanings in doing so. From the perspective of the Daubert analysis, Dukes does not substantially affect the Daubert class action cases, because it does not really address Daubert.

Some commentators have over-characterized Dukes as resolving the split in the circuits over Daubert and class action litigation, discussed in the following sections of this chapter. In reality, Dukes addresses the Daubert issues in the Hydrogen Peroxide line of cases only in dicta, writing: “[t]he District Court concluded that Daubert did not apply to expert testimony at the certification stage of class-action proceedings. 222 F.R.D., at 191. We doubt that is so.” Dukes at 354. As a result, the cases that controlled the use of the Daubert criteria in class certification before Dukes still control the use of Daubert criteria in class certification after Dukes.