u… employment … practices. Itis … supervisors can be the basis of Title VII liability under a disparate-impact theory—since “an employer’s undisciplined system of subjective decisionmaking can have precisely the same effects a sa system pervaded by … such a claim in common. To the contrary, left to their own devices most managers in any corporation—and surely most managers in a corporation that forbidssex discrimination— … criteria for hiringand … as scores on general aptitude tests or educational achievements, see Griggs v. Dukewer Co., … such a company, demonstrating the invalidity of one manager’s use of discretion willdo nothing … seeking to certify a nationwide class … the answers to common questions. Respondents have notified a common mode … have rejected. In a company of Wal-Mart’s size and geographical scope,it is … quiteunbelievable that … analyses performed by Dr. Richard Drogin, a statistician, and Dr. Marc Bendick, a labor economist. Drogin conducted his analysis region-by-region, comparing the number ofwomen … (internal quotation marks omitted). Bendick compared work-force data from Wal-Mart and competitive retailers and concluded that Wal-Mart “promotes a lower percentage of women than its competitors.” Ibid. Even if they are taken atfacevalue, these … In Falcon, we held that one named plaintiff ’s experience ofdiscrimination … of inference arises here. As Judge Ikuta observed in her dissent, “information about disparitiesat … regionaland … national level … A regional pay disparity, for example, may be attributable to only a small set of Wal-Mart stores, and cannot by itself establish the uniform,