Yes. Mr. Delbeke could probably deal with this as well.
By no means am I a technical expert on this, but I think the biggest problem is simply “truing up”. When you're doing an intensity-based system, you basically have to make an estimate at the beginning of the year of how many megatonnes you would expect that reduction to provide. Then you can put those megatonnes on the market for trading purposes, and then at the end of the year you have to verify how many reductions it actually provided. It can be done, but it represents one more little wrinkle in terms of the overall efficiency of the system.
I would also point out that in the United States it's sort of “let a thousand flowers bloom” time as far as the different cap and trade systems that are being proposed. There are systems being developed in New England, in California, and there are over a dozen proposals on the Hill right now in terms of these emissions trading proposals. Of all of them, only one, proposed by Senator Bingaman from New Mexico, is an intensity-based system.
There are a couple of other Canadian wrinkles as well that are seriously being considered and have been considered for the last few years. The other one relates to the technology investment fund. There is quite a bit of interest in the United States in some kind of technology wrinkle in part of the system, so I wouldn't be surprised if that is somehow captured. And also, in terms of some kind of price signal or price cap, the jury is split as to whether or not an American system would eventually provide that.