lawsuit-litigationClass action lawsuits are not only a very common form of civil litigation but, to many law firms and attorneys, they represent the majority of their cases. Accordingly, since the Supreme Court has, in the past two years, considered and reconsidered the relevance and admissibility of expert evidence in class actions, every civil litigator should stand up and take notice.


The U.S. Supreme Court first began closely examining the issue of expert witness evidence and its admissibility in class actions in 2011. See, e.g., Wal-Mart Stores, Inc. v. Dukes, 131 S.Ct. 2541 (2011). To understand the importance of the Court’s 2011 ruling, one legal commentator noted that: “Since its debut…Wal-Mart Stores, Inc. v. Dukes…has become one of the most often cited Supreme Court decisions… . Dukes…is singularly responsible for the demise of numerous class action cases and has even led to the decertification of classes in at least two different federal courts… . In the Dukes opinion, Justice Scalia…took direct aim at the Plaintiffs’ expert, and, in fact, concluded that the Court could “safely disregard” anything the expert had to say.”  Patricia Taylor, “The Impact of Wal-mart Stores, Inc. v. Dukes on Expert Witness Testimony,” Reuters (Oct. 12, 2011).

Some legal analysts indicate that today, class action employment discrimination lawsuits will become much harder to certify. Id. However, what Dukes underscored was not that experts are irrelevant to such cases (or other civil class-action suits), but rather, that expert testimony will be the key in determining whether or not a class should be certified, by showing, for example, a pattern or practice of general workplace bias.

What the Supreme Court is doing now and what to do about it

Since then, the Court has reconsidered its opinion in Dukes and tried to set parameters for when expert testimony is sufficient to certify a class.  In a 2012 case, the Supreme Court attempted to resolve “Whether a district court may certify a class action without resolving whether the plaintiff class has introduced admissible evidence, including expert testimony, to show that the case is susceptible to awarding damages on a class-wide basis.”  See Comcast v. Behrend, (No. 11-864), (Retrieved May 7, 2013). Comcast v. Behrend, which also involved the requirements for class certification, was decided narrowly, in a 5-4 decision that indicated the importance of Federal Rule of Civil Procedure (FRCP) 23. See Robert E. Connolly et. al, Comcast v. Behrend: Supreme Court overturns class certification, upholds Rule 23 ‘rigorous analysis,’” (Apr. 4, 2013).

Attorneys need to be prepared, in civil class actions, to meet the Rule 23 standard in the Federal Rules of Civil Procedure, in order to satisfy the lower courts that class certification is appropriate.  This, in turn, will definitively require expert testimony, and a certain type of testimony, at that. What both the Supreme and lower courts seem to be looking for is testimony by an expert or experts that indicates distinct biases or prejudices by a defendant, that an expert can demonstrate through credible evidence. What is credible? While there is no set legal standard, courts seem to favor testimony that studies the trends of a defendant over a period of time (particularly the period in which the plaintiffs claim that some form of malfeasance took place), analyzes those trends in a statistical manner, and can show, both through verbal opinions and the use of graphs or charts that demonstrate widespread problems, that the class at issue was indeed, experiencing some form of fairly universal discrimination.

Mathematicians, statisticians, and experts who are highly familiar with a particular defendant’s patterns or practices are critical for attorneys who wish to certify a class and proceed to bring suit against the defendant. Defense attorneys should be aware of Comcast and use it to their advantage, but they should be wary of relying solely upon Comcast. Defense lawyers must be equipped with experts of their own, who can disprove the plaintiffs’ contention of widespread, actionable behavior.  Plaintiff’s attorneys have their work cut out for them: Use Rule 23 as a baseline, be aware of Comcast, and always have experts available to prove to judges why a class should be certified. Comcast also underscored the need for experts to offer theories and evidence to prove damages and liability, which should be noted by all attorneys, on either side.


Comcast very much changed the playing field, in terms of expert testimony and class actions, but it by no means dispensed of the need for experts; if anything, it highlighted the need for them. Attorneys on both sides should consult their expert witnesses early and often and should expect that, due to the recent Supreme Court rulings, class actions are not a thing of the past, but attempting to certify them without the aid of experts may be.

By: Kat Hatziavramidis, Attorney-at-Law