&gt; Wouldn&#x27;t the world be flush with Portugal&#x27;s product in both industries rather than only in wine?<p>It depends on the difference in value for both industries, compared to the difference in productivity for both countries. That&#x27;s why it&#x27;s called comparative advantage. If a product is massively more valuable than the other one, then it could make sense to specialize on it, even if the other country is much less productive. The classic example is, a professor can type faster than their secretary, but it still makes sense for them to specialize on their field and let the secretary do the typing.