Joinder’s Diversity Asymmetry

Authors

• Jason J. Jarvis, Pepperdine Caruso Law

Keywords

Diversity jurisdiction; supplemental jurisdiction; joinder rules; nondiverse party joinder; Federal Rules of Civil Procedure; FRCP; Rule 14; Rule 19; Rule 20; Rule 24; 28 U.S.C. § 1367(b); Kroger; game theory; federal court; state court; removal; pendent jurisdiction; ancillary jurisdiction

Abstract

In federal diversity cases, plaintiffs are barred from joining nondiverse supplemental parties or claims under 28 U.S.C. § 1367(b). Defendants, however, can expand the case without the same restriction. Section 1367(b) codified the U.S. Supreme Court’s concern in Owen Equipment & Erection Co. v. Kroger: Plaintiffs might so prefer federal court that they would “sneak” nondiverse parties in by hiding them until after diversity jurisdiction is established, only then springing them on unsuspecting courts and defendants. This Article challenges the justification for that asymmetry in three ways.

First, it explores the history of the asymmetry, starting with how joinder rules developed as cases went from simple unilateral actions to the multiparty ecosystems of today, before examining the history of diversity and the supplemental jurisdiction statute. Second, it considers the theoretical bases for assumptions about jurisdictional preferences and how litigants achieve them, finding that the theory underlying the Court’s concern in Kroger is irrational. Third, the Article shares the results of an original study analyzing dispositive motions based on joinder and diversity jurisdiction in over 1,400 federal cases. The data show a pervasive inconsistency in the ways courts have attempted to address the asymmetry, even thirty-five years after the statute’s enactment, creating uncertainty for litigants and inefficiency for courts. Taken together, the history, theory, and data show that the current rule produces structural inequality and procedural inefficiency. The asymmetry is an anachronism undercut by modern litigation tactics and disparate court resolutions. This Article concludes with a modest proposed revision to the statute that would eliminate the asymmetry in § 1367(b) while preserving diversity jurisdiction as a whole.

Recommended Citation

Jason J. Jarvis, Joinder’s Diversity Asymmetry, 95 Fordham L. Rev. 623 (2026).
Available at: https://ir.lawnet.fordham.edu/flr/vol95/iss2/8