The United States Supreme Court recently heard oral argument in a case, Comcast Corp. v. Behrend, involving the standard for class certification. I drafted an amicus brief on behalf of the American Antitrust Institute and the American Independent Business Alliance.
The decision to certify a class can determine the outcome of litigation. Often, the stakes in an individual case are too small for its prosecution to make economic sense. Class certification allows a small number of plaintiffs to sue on behalf of a much larger group, giving rise to economies of scale. As a result, unless a court certifies a class, a defendant may be able to get away with violating the law simply because no one can afford to challenge its conduct in court. So changes in the class certification doctrine can have significant consequences. But those consequences can be difficult to predict because of the complexity of class certification doctrine.
Indeed, the law governing class certification is such a dense thicket that it is hard to know what issues the Court is interested in addressing in Comcast. One possibility is whether plaintiffs have to provide admissible evidence in support of class certification. To be more precise, must plaintiffs provide expert testimony that meets the Daubert standard? Daubert requires courts to determine whether expert testimony relies on “junk science” or legitimate science. The Court framed the briefing before it in a way that would allow the parties to address this question.
The Court had suggested in an opinion in 2011, Wal-Mart Stores, Inc. v. Dukes, that Daubert applies to class certification. But that was mere dicta. The Court might use Comcast to make its earlier suggestion the law. If so, the result would be neither surprising nor all that significant. To be sure, briefs and hearings on Daubert would make an already cumbersome and expensive class certification process that much more cumbersome and expensive. And, given that it is difficult to get class action lawyers to take a case, at the margins some legal violations would go without redress. Yet it is unlikely the outcome in many cases would change. A judge who doubts the legitimacy of a plaintiff’s expert testimony would be very unlikely to grant class certification whether or not she were to rule the testimony inadmissible under Daubert.
But the Court might not limit itself to the Daubert issue in Comcast for a couple of reasons. First, the plaintiffs made a strong argument that the defendant, Comcast, had waived any objection it might make based on Daubert by failing to raise it before the trial court judge. Second, the way the Court framed the issue on certiorari would allow it to go beyond ruling on how a plaintiff must prove class certification is appropriate—on the kind of evidence a plaintiff must provide. It could permit the Court to rule on what showing plaintiffs must make at class certification. That issue, it turns out, is very tricky.
The amicus brief I wrote was designed to help the Court avoid including loose language in its opinion that might inadvertently transform what the plaintiff must show to get a class certified. Lower courts have developed complicated and at times inconsistent rules on the issue. Some courts have noted, for example, that a plaintiff must be able to use common evidence to show harm to a significant proportion of the members of a class—likely a number larger than a simple majority—but not necessarily to show harm to all class members, much less to prove the precise amount of damages suffered by each class member. Included in this camp is the Seventh Circuit, particularly in opinions written by Judge Richard Posner. Other courts, however, have implied—although they have not held—that plaintiffs must use common evidence to show harm to all or virtually class members. And yet other courts have noted that individual damages issues should rarely, if ever, by themselves prevent class certification.
As I hope these examples illustrate, the rules governing class certification are subtle and complicated. Indeed, the justices seemed confused at the oral argument in Comcast about just what it is the plaintiffs must show for a court to certify a class. And the advocates did not seem to cure that confusion. Moreover, the parties’ briefs paid relatively little attention to the showing plaintiffs must make to get a class certified. As a result, Comcast would provide a poor means to clarify this crucial issue. My hope is that the Court addresses only Daubert for the time being. If it were to go further, it would risk unintended and undesirable consequences.
To read the full brief that I co-authored on behalf of the American Antitrust Institute and the American Independent Business Alliance, click here.