The Wealth of Nations by Part 4 Chapter 7 Page 116

produce which England exchanges for those enumerated commodities, she must get a better price than any other countries can get for the like parts of theirs, when they exchange them for the same commodities. The manufacturers of England, for example, will purchase a greater quantity of the sugar and tobacco of her own colonies than the like manufactures of other countries can purchase of that sugar and tobacco. So far, therefore, as the manufactures of England and those of other countries are both to be exchanged for the sugar and tobacco of the English colonies, this superiority of price gives an encouragement to the former beyond what the latter can in these circumstances enjoy. The exclusive trade of the colonies, therefore, as it diminishes, or at least keeps down below what they would otherwise rise to, both the enjoyments and the industry of the