Usdc-Casa

This mandamus petition requires us to decide whether, under Erie R. Co. v. Tompkins, 304 U.S. 64 , 58 S.Ct. 817 , 82 L.Ed. 1188 (1938), a federal court sitting in diversity applies state or federal law to determine the validity of a pre-dispute jury trial waiver contained in a contract governed by California law. California and federal law treat such waivers differently: Under California law, pre-dispute jury trial waivers are invalid unless expressly authorized by statute. See Grafton Partners, L.P. v. Superior Court, 36 Cal.4th 944 , 32 Cal.Rptr.3d 5 , 116 P.3d 479 (2005). Federal law, on the other hand, permits such waivers as long as each party waived its rights knowingly and voluntarily. See Palmer v. Valdez, 560 F.3d 965, 968 (9th Cir.2009). “The compatibility of these provisions, in an action based on [California] law but tried in federal court by reason of the parties’ diverse citizenship” implicates the Erie doctrine. Gasperini v. Ctr. for Humanities, Inc., 518 U.S. 415, 419 , 116 S.Ct. 2211 , 135 L.Ed.2d 659 (1996). “Under the Erie doctrine, fed eral courts sitting in diversity apply state substantive law and federal procedural law.” Id. at 427 , 116 S.Ct. 2211…