An Empirical Study of Class-Action Appeals

55 Pages Posted: 20 May 2020 Last revised: 27 Jul 2020

See all articles by Bryan Lammon

Bryan Lammon

University of Toledo - College of Law

Date Written: April 30, 2020


Federal Rule of Civil Procedure 23(f) allows parties in a class action to petition the court of appeals for immediate review of class-certification decisions. Criticisms of the rule are common. Some see Rule 23(f) as a defendant-favoring tool for dragging out litigation and ensuring that no class is certified. Others contend that the rule is inconsistently applied among the circuits and should be replaced with a right to appeal. Yet there is little reliable data on how the courts have applied Rule 23(f).

To bring some hard data to this discussion, I collected all petitions to appeal from class-certification decisions under Federal Rule of Civil Procedure 23(f) that parties filed from 2013 through 2017. The data revealed three insights on Rule 23(f) and class actions generally. First are the basic findings—the number of petitions the rate at which different courts grant them, and what those courts do (affirm or reverse) after granting a petition. Second, empirical testing found little support for either of the above-mentioned criticisms. And third, the data shows one corner of the class-action universe in which plaintiffs are not predominantly losing: in the Rule 23(f) context, the courts of appeals reached a plaintiff-favorable outcome over 50% of the time.

Keywords: Class Actions, Civil Procedure, Federal Jurisdiction, Appellate Jurisdiction, Interlocutory Appeals

Suggested Citation

Lammon, Bryan, An Empirical Study of Class-Action Appeals (April 30, 2020). Available at SSRN: or

Bryan Lammon (Contact Author)

University of Toledo - College of Law ( email )

2801 W. Bancroft Street
Toledo, OH 43606
United States

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