That's a very good question.
What we do is project on the basis of government balance. Our assumption, as we've prepared our report, is that governments at all levels will basically bring in balanced budgets and operate in balance over the course of the projection period, which runs to 2009.
Now, that is an assumption, but it seems to be largely consistent with what has happened both federally and provincially, provided our projections, in terms of nominal GDP growth, actually turn out to be right. As all members of the committee know, government revenues are largely contingent on nominal GDP growth, and that has been running, up until recently, considerably higher than real because we've had favourable terms of trade.
Our projection, actually, has those favourable terms of trade flattening out and coming down, which ought to mean that the very good revenue performance that we've seen both federally and provincially ought to flatten out a little bit.
Now, that's purely a projection. So far we, in Canada, as a number of other countries, have been a bit surprised at how fast personal income tax revenues have grown relative to the growth of personal income. We don't fully understand why. In part, it may have to do with income distribution. We're not absolutely sure. But probably, at least for 2007, if there were a risk on the government balance side, the risk is that government balances will be a little more favourable than our assumption of being in balance.