In Stockwell v. City and County of San Francisco, ___ F.3d ___ (9th Cir. April 24, 2014), the Ninth Circuit Court of Appeals reversed the order of the U.S. District Court for the Northern District of California (Judge Hamilton) denying plaintiff’s motion for class certification on claims of age discrimination.

Plaintiffs were police officers who filed a class action on behalf of themselves and certain other officers over age 40 who they claimed suffered from disparate impact age discrimination as the result of defendant’s decision to base promotional decisions on a new examination. According to plaintiffs, defendant simply abandoned the prior examination used – and dominated by older officers.  The district court denied plaintiff’s motion for class certification on the grounds that the claims lacked commonality under Federal Rule of Civil Procedure 23(a).  Plaintiffs filed an interlocutory appeal.

The appellate court reversed, finding that the district court improperly evaluated the merits of plaintiffs’ action, “rather than focusing on whether the questions presented, whether meritorious or not, were common to the members of the putative class. By doing so, the district court made an error of law and relied on improper factors, thereby abusing its discretion.” Here, plaintiffs “identified a single, well enunciated, uniform policy that, allegedly, generated all the disparate impact of which they complain: [defendant]’s decision to make investigative assignments using the [new examination] List instead of the [old examination] List. Each member of the putative class was on the [old] List. Each suffered the effects of its elimination, whatever those were.” The court then went on to note that once a specific practice is identified in a disparate impact case, the next question is whether that practice had a disproportionate adverse impact on otherwise eligible officers over forty.  Thus, a party asserting such a claim must demonstrate a statistical disparity affecting members of the protected group. In this case, plaintiffs did produce a statistical study purportedly showing a disparate impact but the district court determined that it was inadequate “for — among other reasons — failing to conduct a regression analysis to take account of alternative explanations, unrelated to age, for any statistical imbalance. But whatever the failings of the class’s statistical analysis, they affect every class member’s claims uniformly . . . .  Each member of the putative class suffered the effects of eliminating the [old]  List. If those effects amount to a disparate impact on account of age, it will be so for all class members or for none; their claims rise and fall together.”