That is a good question. Tax evasion is difficult to counter precisely because it is a covert practice. So we do not necessarily have information on that. The treaties give us the ability to approach another country when we have reason to believe that the government or institutions in that country have information pertaining to the administration of taxes in Canada. I cannot say that it is the complete and total solution, but it is certainly an important tool that will make the job of the Canada Revenue Agency easier.
On October 4th, 2010. See this statement in context.