Messner v. Northshore University HealthSystem

Dist. Ct. erred in denying plaintiffs' request for class certification in action alleging that defendant's merger with another hospital violated section 7 of Clayton Act where, according to plaintiffs, result of merger was higher prices for hospital services for individual patients and third-party payors. Basis for denial was Dist. Ct.'s erroneous conclusion that plaintiffs' expert had conceded away validity of his common method by which he proposed to show antitrust impact that merger had on members of proposed class. Moreover, lack of uniformity in defendant's price increases did not require denial of class certification where plaintiff's expert's difference-in differences methodology could properly estimate anti-trust impact of said price increases. Additionally, record showed that common questions of other liability issues were sufficient to satisfy prerequisites for class action treatment under Rule 23(b)(3).