The Court first reviewed general class certification principles, including the principle that demonstrating commonality "does not require proof that the putative class will prevail on whatever common questions it identifies." Slip op. at 7-12.
The Court then considered "the only question properly before [it] — whether the district court’s denial of the [plaintiffss'] motion for class certification was an abuse of discretion." The Court held that the district court abused its discretion by evaluating merits issues in denying certification "rather than focusing on whether the questions presented, whether meritorious or not, were common to the members of the putative class." Slip op. at 13-19. Here, the plaintiffs identified a "single, well-enunciated, uniform policy" that allegedly generated the alleged disparate impact.
In short, the officers are all challenging a single policy they contend has adversely affected them. The question whether the policy has an impermissible disparate impact on the basis of age necessarily has a single answer. To so recognize is in no way to approve of the statistical showing the officers have made as adequate to make out their merits case. Nor does identifying a common question sufficient for Rule 23(a)(2) purposes entail any disagreement with the City’s contention that proper statistical analysis would negate any disparate impact traceable to age — or, for that matter, to prejudge any other argument or defense the City may offer. The defects the City has identified may well exist, but they go to the merits of this case, or to the predominance question.... Given the interlocutory nature of this appeal, and its consequent limitation to class certification factors only, we may not consider the merits questions, even as an alternative ground for affirmance.
Slip op. at 18-19. The Court declined to address predominance because the district court did not rule on it, and the parties did not brief it on appeal. Slip op. at 19-20.
Stockwell v. City and County of San Francisco is available here.