You're still going to miss externalities when you limit the factors you consider. Sure, lumber sellers in Canada could do well and the US could avoid cutting downt heir own trees, but can we really assume that deforedtstion in Canada would be without consequence?
Assuming that stripping resources from other parts of the world is how we got into this ecological mess in the first place.
Assuming that stripping resources from other parts of the world is how we got into this ecological mess in the first place.