The Third and Seventh circuits have reached a sharp divide during the past year over the meaning of the implied “ascertainability” prerequisite to class certification. The Third Circuit affirmed a narrow version of ascertainability in Byrd v. Aaron’s Inc., 784 F.3d 154, 168 (3d Cir. 2015), but several months later the Seventh Circuit refused the defendant’s invitation to do likewise in Mullins v. Direct Digital, LLC, 795 F.3d 654, 657 (7th Cir. 2015).
Both circuits agree that before a class may be certified, it must be ascertainable. The difficulty arises in determining exactly what requirements the ascertainability prerequisite entails. The Third Circuit’s decision in Byrd attempted to provide clarification, holding that ascertainability “consists of nothing more” than two inquiries: a plaintiff must show that “(1) the class is defined with reference to objective criteria; and (2) there is a reliable and administratively feasible mechanism for determining whether putative class members fall within the class definition.” Notably, identifying class members via affidavit is not considered administratively feasible by the Third Circuit, which had refused to sanction class member identification made by “no more than . . . potential class members’ say-so” in Marcus v. BMW of North America, LLC, 687 F.3d 583 (3d Cir. 2012) and Carrera v. Bayer Corp., 727 F.3d 300 (3d Cir. 2013).
It was this “administratively feasible mechanism” requirement that the Seventh Circuit took issue with in Mullins. “These courts [applying the narrow ascertainability standard] have moved beyond examining the adequacy of the class definition itself to examine the potential difficulty of identifying particular members of the class and evaluating the validity of claims they might eventually submit.” Mullins v. Direct Digital, LLC, 795 F.3d 654, 657 (7th Cir. 2015). Rather, a district court should be satisfied that a class is ascertainable so long as the class is defined clearly with reference to objective criteria. Id. Concerns about the practicality of identifying class members are properly addressed within the context of Rule 23(b)(3), which already mandates consideration of “the likely difficulties in managing a class action,” while balancing countervailing interests to decide whether a class action “is superior to other available methods for fairly and efficiently adjudicating the controversy.” Id. at 658. To focus on administrative feasibility at the expense of the other Rule 23 factors is to “erect a nearly insurmountable hurdle at the class certification stage in situations where a class action is the only viable way to pursue valid but small individual claims.” Id. at 662.
Other circuits have begun to take sides. See Karhu v. Vital Pharmaceuticals, Inc., – Fed.Appx. –, 2015 WL 3560722, at *2–4 (11th Cir. June 9, 2015) (unpublished) (adopting the narrow version of ascertainability and declining to permit class identification via affidavit), and Rikos v. Procter & Gamble Co., 799 F.3d 497, 525 (6th Cir. 2015) (retaining the broad version, “see[ing] no reason to follow Carerra” and noting that the Third Circuit’s approach had received criticism from several other courts).
Any hope of a tiebreaker from the Supreme Court was dashed when the justices recently declined to review the Seventh Circuit’s decision in Mullins. At least for the foreseeable future, class action defendants’ ability to rely on the ascertainability standard to avoid class certification will depend on which circuit they find themselves in.
 A more detailed discussion of the Byrd decision can be found in our previous blog post here.