The Wealth of Nations by Part 4 Chapter 6 Page 1

Of Treaties of Commerce

When a nation binds itself by treaty either to permit the entry of certain goods from one foreign country which it prohibits from all others, or to exempt the goods of one country from duties to which it subjects those of all others, the country, or at least the merchants and manufacturers of the country, whose commerce is so favoured, must necessarily derive great advantage from the treaty.

Those merchants and manufacturers enjoy a sort of monopoly in the country which is so indulgent to them. That country becomes a market both more extensive and more advantageous for their goods: more extensive, because the goods of other nations being either excluded or subjected to heavier duties, it takes off a greater quantity of theirs: more advantageous, because the