As I said, I think a carbon tax offers certain advantages in the sense that it's less easily manipulated by the participants. The reason the European trading system is having problems is that businesses convinced governments that they needed more permits than they actually did, and that created an opportunity for windfall profits because companies were able to sell permits they never were going to need. Now it has also created a system in which permits under the European system are almost without value, because the number of permits exceeds the amount of emissions.
When Canada, under the previous Liberal government, was developing the large final emitters system, I would say we were on the brink of falling prey to that same problem. Government was having to rely on industry to provide business as usual projections for the year 2012, and those projections were inflated. If that system had gone ahead, we would have been in the same situation as Europe. Companies, including oil sands operators, would have been selling their credits and making money by selling emissions credits. At the end of the day, that system would not have resulted in an absolute reduction in greenhouse gas emissions.