information:extraction, structural:reformatting, linguistic:voice_change, structural:summarization, structural:expansion
Hanna

Under the approach in Hanna v. Plumer, the federal court of a state hearing a case based on diversity jurisdiction should apply state law in the event of conflict between state and federal law - or in the absence of relevant federal positive law - if the state law deals with substantive rights of state citizens. The Supreme Court has defined substantive rights as, "rights conferred by the law to be protected and enforced by the adjective law of judicial procedure." An example of a substantive right would be a state law on fraud, which may vary widely in composition depending on the jurisdiction. If the state law is merely procedural, or relating merely to the form and mode of judicial operations, then the federal court does not have to apply the conflicting state law. However, the substance-procedure distinction is a generality as the Court rejected any test based upon "litmus paper criterion." Thus, a choice between state and federal law must be made with reference to the underlying policy of the Erie decision.