I wanted to add something about the importance of leaving the responsibility in federal hands.
Canada has tax information exchange agreements and tax treaties with other countries. The federal government has good international coverage. We have people in our office who work on international taxation. Would a province be able to do all that work at no additional cost? It would have to start from scratch. On top of that, would those other countries be willing to sign agreements with a province, as opposed to a country? Those are questions we have.