I'll be glad to give you my thoughts.
We do not have very precise measures on the extent, nature, and structure of evasion. From very indirect types of methods, we know it is substantial. Estimates range between 10% and 15%, and some are a bit higher, on the total potential revenue lost due to evasion of various forms. There are certainly grey areas of compliance, where companies that operate in Canada and in other countries can shift their financing to the countries where they get the higher tax deduction, and shift their revenues through so-called transfer pricing into the jurisdictions that have the lower tax rates. That is not a simple issue for Canada or any country to address.
On your question of whether we can fully eliminate tax evasion, we certainly cannot. No country has been able to do that. No country can fully eliminate it. If you think of small businesses that operate partly in cash and in the underground economy, the best we can do is have our tax enforcement people out there trying to nab a few of them. We cannot nab all of them.
It is a real problem, and the relevant aspect of it is to ask how evasion interacts with our design of the tax system and questions about personal income tax rates: how do we withhold those taxes? Empirical studies have found that the GST has increased the incidence of evasion, because in part it has given small-business people the incentive--