There is a wide variety of techniques, as a matter of fact, some of the more complicated structures devised by the mind of man. A lot of them concern international financial centres, as my colleague has mentioned, and there are ways of essentially moving income out of Canada without actually moving the operations.
You do that by putting a lot of debt, in simple terms, on what's going on in Canada. So you've got lots of interest expense. And the interest income may flow into an international financial centre where it's subject to very low rates of tax, if any tax at all.
Another way, of course, is the double-dip, where you can borrow money in Canada, get a deduction, and invest it in the shares of an offshore company. And then that offshore company itself lends it to another affiliate, which gets another deduction. And therefore you get two deductions per 1¢ of interest expense.
There are complex mechanisms between Canada and the United States involving partnerships whereby, in effect, you can exploit the fact that an enterprise is treated one way in Canada for tax purposes and another way in the United States and get away with very little tax. And there are more and more ways beyond that.
As I said, the tax system is a high-maintenance activity. You have to keep at it all the time, because taxpayers will keep on thinking of ever more elaborate and sophisticated ways to beat the system, and you've got to be able to react.