Yet another un- or underexplored question about Erie Railroad Co. v. Tompkins (parallel posted on Prawfblawg.
Today's question counts only as underexplored, not unexplored (due to Abbe Gluck’s marvelous article): A federal court is interpreting a state statute. Is it obligated by Erie to do so using the state’s method of statutory interpretation? Shouldn’t the answer be based on whether the state supreme court would want the federal court to do so? But, short of certification, how can we know whether that’s true?
Bonus question: A sister state court is interpreting a state’s statute. Is it obligated by the Full Faith and Credit Clause to do so using the state’s method of statutory interpretation?
Double bonus question: A state court is interpreting a federal statute. Is it constitutionally obligated (by the Supremacy Clause?) to do so using federal methods of statutory interpretation?