Plaintiffs in recent antitrust class actions have sought to exclude expert evidence
and opinions offered by defendants’ expert economists with the argument that the experts’ statistical testing of plaintiffs’ proposed methodology does not satisfy the Daubert standard for the admissibility of expert testimony. The statistical testing at issue relates to the determination of whether purported effects from plaintiffs’ regression models estimated on the proposed class as a whole hold when the models are estimated separately for different subsets or different members of a proposed class. Plaintiffs in In re Air Cargo Shipping Services Antitrust Litigation, for example, sought to exclude testimony from defendants’ experts related to this form of testing.The recent
decision in In re Processed Egg Products Antitrust Litigation sheds further light on plaintiffs’ criticisms of such testing. Meanwhile, the very recent decision in Food Lion LLC v. Dean Foods Co. highlights the importance of such testing at the class certification stage.