To understand the gains from international trade, we have to go back to the basic economic problem—
scarcity, which results from our inability to produce as many desirable things as we want. An obvious
implication of scarcity is that we are better off if we can get more of what we want with fewer workers. If
it takes fewer workers to produce food, for example, then we can shift workers into producing more of
other valuable products without sacrificing any food production.