Truth is usually paradoxical.
You never get the right answer by a mixed-up compromise. Better start with the two extremes at once. Only then does the moral question become clear. The first possibility is easier to imagine because we have all been south of the border, at least by way of television. If there was total freedom of goods, no customs or immigration, and we could all move south or north for jobs as we chose, life in our provinces would be like living in New England or North Dakota.