RETROACTIVE APPLICATION OF LAW-A PROBLEM IN CONSTITUTIONAL LAW

May an overruling decision be applied to ascertain the legal effect of prior conduct? In cases arising under the diversity of citizenship jurisdiction, the United States Supreme Court has held that the federal courts should apply earlier state court decisions, and not a decision overruling them, whenever the retroactive application of the new rule would adversely affect a party who had changed his position in reliance on the decisions overruled. In the absence of such reliance and change of position it has sustained the retroactive application of a new rule. If the basis of the first principle is elemental fairness and justice it might be supposed that the due process clauses would require it, since they afford protection against arbitrariness or unfairness either procedural or substantive. It might be supposed further that the same would be true of statutes. While statutes are not applied retroactively unless Congress or legislature so provides either expressly or by implication, the question raised here is the extent to which such provisions are constitutionally valid. The decisions of the United States Supreme Court have been examined for the purpose of ascertaining the extent to which the United States Constitution is a bar to the retroactive application of law, either judge-made or statutory