Not so fast, said the Supreme Court. Following the Supreme Court's Wal-Mart Stores v. Dukes decision (discussed here), the Supreme Court vacated the Ninth Circuit's decision in this case. The Ninth Circuit decided that Wal-Mart requires reconsideration of the decision and sent it back to the district court.
Why? The trial court did not apply the proper analysis (after Wal-Mart) to determine whether there is sufficient commonality to certify the class. As explained by the Court:
On remand, the district court must determine whether the claims of the proposed class “depend upon a common contention . . . of such a nature that it is capable of classwide resolution — which means that determination of its truth or falsity will resolve an issue that is central to the validity of each one of the claims in one stroke.” Wal-Mart, 131 S. Ct. at 2551.So, it's not enough that there are "common questions" in the abstract, because, as the Ninth Circuit stated (quoting Wal-Mart and its own later decision in Ellis v. Costco):
"any competently crafted class complaint literally raises common questions.” Wang [sic], 131 S. Ct. at 2551 (alteration and internal quotation marks omitted). “What matters to class certification is not the raising of common questions — even in droves — but, rather the capacity of a classwide proceeding to generate common answers apt to drive the resolution of the litigation.” Id. (alteration and internal quotation marks omitted). Dissimilarities within the proposed class may “impede the generation of common answers.” Id. “If there is no evidence that the entire class was subject to the same allegedly
discriminatory practice, there is no question common to the class.” Ellis v. Costco Wholesale Corp., 657 F.3d 970, 983 (9th Cir. 2011).
the court finds that the questions of law or fact common to class members predominate over any questions affecting only individual members, and that a class action is superior to other available methods for fairly and efficiently adjudicating the controversy.
Employers are also entitled to litigate any individual affirmative defenses they may have to class members’ claims. Id. at 2561.