With the U.S. Supreme Court making the test for class actions tougher, you may see a short-term increase in denials of class treatment. You may as a result also witness a surge in class members' filing cases where they assert the now-dead class claims on an individual basis.

But what if — as often happens — the statute of limitations has run while the class action case lived? Can the class members' lawsuits proceed anyway?

Since American Pipe & Construction Co. v. Utah, 414 U.S. 538 (1974), federal courts have answered yes — so long as the class and individual claims arose under federal law. Does the same rule apply to state law claims?

The Second Circuit last week joined the Fifth and Ninth Circuits in holding that state law, and not American Pipe, governs the question of whether a class action stops a state statute of limitations from running. Casey v. Merck & Co., Inc., No. 10-1137-cv (2d Cir. Aug. 5, 2011). The panel also ruled that the state whose law applied to the plaintiffs' claims hadn't spoken clearly on whether it would permit American Pipe-style tolling. The court therefore certified questions to the Supreme Court of Virginia.