Fed. R. Evid. 302
In a civil case, state law governs the effect of a presumption regarding a claim or defense for which state law supplies the rule of decision.
28 APPENDIX U.S.C. § 302
NOTES OF ADVISORY COMMITTEE ON PROPOSED RULESA series of Supreme Court decisions in diversity cases leaves no doubt of the relevance of Erie Railroad Co. v. Tompkins, 304 U.S. 64, 58 S.Ct. 817, 82 L.Ed. 1188 (1938), to questions of burden of proof. These decisions are Cities Service Oil Co. v. Dunlap, 308 U.S. 208, 60 S.Ct. 201, 84 L.Ed. 196 (1939), Palmer v. Hoffman, 318 U.S. 109, 63 S.Ct. 477, 87 L.Ed. 645 (1943), and Dick v. New York Life Ins. Co., 359 U.S. 437, 79 S.Ct. 921, 3 L.Ed.2d 935 (1959). They involved burden of proof, respectively, as to status as bona fide purchasers, contributory negligence, and non-accidental death (suicide) of an insured. In each instance the state rule was held to be applicable. It does not follow, however, that all presumptions in diversity cases are governed by state law. In each case cited, the burden of proof question had to do with a substantive element of the claim or defense. Application of the state law is called for only when the presumption operates upon such an element. Accordingly the rule does not apply state law when the presumption operates upon a lesser aspect of the case, i.e. "tactical" presumptions.The situations in which the state law is applied have been tagged for convenience in the preceding discussion as "diversity cases." The designation is not a completely accurate one since Erie applies to any claim or issue having its source in state law, regardless of the basis of federal jurisdiction, and does not apply to a federal claim or issue, even though jurisdiction is based on diversity. Vestal, Erie R.R. v. Tompkins: A Projection, 48 Iowa L.Rev. 248, 257 (1963); Hart and Wechsler, The Federal Courts and the Federal System, 697 (1953); 1A Moore, Federal Practice 0.305[3] (2d ed. 1965); Wright, Federal Courts, 217-218 (1963). Hence the rule employs, as appropriately descriptive, the phrase "as to which state law supplies the rule of decision." See A.L.I. Study of the Division of Jurisdiction Between State and Federal Courts, §2344(c), p. 40, P.F.D. No. 1 (1965).
COMMITTEE NOTES ON RULES-2011 AMENDMENT The language of Rule 302 has been amended as part of the restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.