I have two quick points. I would agree with Professor Moore on the notion that North America provides a laboratory for this. I'm not a big fan of transfers for credits, because the accounting issues are phenomenal in keeping all of that straight. Is it permanent? Is it temporary? Does it matter? There's all of that kind of stuff to consider. I think it's a make-work project for public servants, who I think have better things to do with their time than that kind of thing.
Down the road, I would see something tied much more to the World Trade Organization, as part of that sort of system. If we want to expand much beyond North America, that's a road I would see worth exploring.