1) The last Pennsylvania Supreme Court opinion on point is an 80-year old case. You think they would decide otherwise now. The change in the law would be to your benefit. Your case is a diversity case. Where do you sue, in a Pennsylvania state trial court or in a federal district court?

2) You are federal district judge in the E.D. Va. The only cases on point are a 20-year-old decision by the 4th Circuit and conflicting 5-year-old decision by a Va trial court. Is the 4th Circuit decision binding authority for you?

3) Assume that under New York law, a New York state court ascertaining the law of a sister state does not use the prediction model of Bernhardt. It instead acts like a lower court of the sister state and simply follows old decisions by the Supreme Court of the sister state, even if it is likely that this Supreme Court of the sister state would overrule the old precedent.

P (from Michigan) sues D (from New York) in federal court in New York concerning an accident that P and D got into in Michigan. Under New York choice of law rules, Michigan law would apply. There is an old case from the Michigan Supreme Court adopting a contributory negligence rather than a comparative fault approach. But it is very likely that the Michigan SCt would adopt comparative fault now. What does the federal court in New York do, follow the old case or predict what the Michigan Supreme Court would do now?