Well, when you say “been shown”—I'm an economist—it's easy to make these statements, that “The evidence shows unequivocally”—but economists aren't really quite as certain as you make them out to be.
Can you describe, in precise terms, what is your evidence or proof? I don't deny you're right, but I would like to know the proof that external foreign direct investment through Barbados enhances Canadian productivity. How do you know that?