Pendent Jurisdiction

Pendent jurisdiction is the authority of a United States federal court to hear a closely related state law claim against a party already facing a federal claim, described by Justice Antonin Scalia as "jurisdiction over nonfederal claims between parties litigating other matters properly before the court." Such jurisdiction is granted to encourage both "economy in litigation," and fairness by eliminating the need for a separate federal and state trial hearing essentially the same facts yet potentially reaching opposite conclusions.
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District courts have discretion to hear pendent state claims where there is a substantial federal claim arising out of a common nucleus of operative fact. 28 U.S.C. S 1367(a); United Mine Workers v. Gibbs, 383 U.S. 715 (1966). This is a "doctrine of flexibility, designed to allow courts to deal with cases involving pendent claims in the manner that most sensibly accommodates a range of concerns and values." Carnegie-Mellon Univ. v. Cohill, 484 U.S. 343, 350 (1988).

The court must weigh "considerations of judicial economy, convenience and fairness to the litigants; if these are not present a federal court should hesitate to exercise jurisdiction over state claims." Gibbs, 383 U.S. at 726. However, "[n]eedless decisions of state law should be avoided both as a matter of comity and to promote justice between the parties, by procuring for them a surer-footed reading of applicable law." Id. If "state issues substantially predominate, . . . the state claims may be dismissed without prejudice and left for resolution to state tribunals." Id., 383 at 726-27.