The New Consensus on Class Certification: What it Means for the Use of Economic and Statistical Evidence in Meeting the Requirements of Rule 23
David S. Evans
Global Economics Group; University College London
Offering expert testimony that is a hair's breadth away from nutty is no longer sufficient to secure class certification according to an emerging consensus across the circuit courts. The court must also get into any merits issues that are relevant to the class issues. As a practical matter credible expert testimony will prove more important going forward in all types of class certification for both plaintiffs and defendants. This note summarizes the consensus that is emerging and describes the sorts of analyses that will prove critical in seeking or opposing the certification of a particular class.
Number of Pages in PDF File: 15
Keywords: class certification, economic evidence, statistical evidence, Rule 23, expert testimony
JEL Classification: K00
Date posted: January 21, 2009