How have courts determined "commonality" in a class action alleging discrimination based on national origin?

In Parra v. Bashas', Inc., 536 F.3d 975 (9th Cir. 2008), the court found "commonality" for a class which alleged discrimination based on national origin, which caused Hispanic employees to receive lower pay. Plaintiffs presented evidence from which the district court found Hispanic workers' hourly rates were lower in similar jobs. The district court, nonetheless, denied certification for lack of "commonality" as to pay discrimination because defendant had rectified future pay disparities. On appeal, the appellate court reversed stating that the district court failed to address certification for the past wrongs. The court said plaintiffs had shown commonality because "the Plaintiffs here establish commonality even though their individual factual situations differ because they all seek a common legal remedy for a common wrong. Plaintiffs here not only presented evidence of discriminatory pay scales, but also provided statistical and anecdotal evidence of discrimination." Id. at 989. Thus, the pay disparities among the class member did not prevent certification because they all suffered from the same discriminatory practice.