Wealth of Nations IV-2-6
Thus, upon equal or nearly equal profits, every wholesale merchant naturally prefers the home-trade to the foreign trade of consumption, and the foreign trade of consumption to the carrying trade. In the home-trade his capital is never so long out of his sight as it frequently is in the foreign trade of consumption. He can know better the character and situation of the persons whom he trusts, and if he should happen to be deceived, he knows better the laws of the country from which he must seek redress. In the carrying trade, the capital of the merchant is, as it were, divided between two foreign countries, and no part of it is ever necessarily brought home, or placed under his own immediate view and command. The capital which an Amsterdam merchant employs in carrying corn from Konigsberg to Lisbon, and fruit and wine from Lisbon to Konigsberg, must generally be the one half of it at Konigsberg and the other half at Lisbon. No part of it need ever come to Amsterdam. The natural residence of such a merchant should either be at Konigsberg or Lisbon, and it can only be some very particular circumstances which can make him prefer the residence of Amsterdam. The uneasiness, however, which he feels at being separated so far from his capital generally determines him to bring part both of the Konigsberg goods which he destines for the market of Lisbon, and of the Lisbon goods which he destines for that of Konigsberg, to Amsterdam: and though this necessarily subjects him to a double charge of loading and unloading, as well as to the payment of some duties and customs, yet for the sake of having some part of his capital always under his own view and command, he willingly submits to this extraordinary charge; and it is in this manner that every country which has any considerable share of the carrying trade becomes always the emporium, or general market, for the goods of all the different countries whose trade it carries on. The merchant, in order to save a second loading and unloading, endeavours always to sell in the home-market as much of the goods of all those different countries as he can, and thus, so far as he can, to convert his carrying trade into a foreign trade of consumption. A merchant, in the same manner, who is engaged in the foreign trade of consumption, when he collects goods for foreign markets, will always be glad, upon equal or nearly equal profits, to sell as great a part of them at home as he can. He saves himself the risk and trouble of exportation, when, so far as he can, he thus converts his foreign trade of consumption into a home-trade. Home is in this manner the centre, if I may say so, round which the capitals of the inhabitants of every country are continually circulating, and towards which they are always tending, though by particular causes they may sometimes be driven off and repelled from it towards more distant employments. But a capital employed in the home-trade, it has already been shown, necessarily puts into motion a greater quantity of domestic industry, and gives revenue and employment to a greater number of the inhabitants of the country, than an equal capital employed in the foreign trade of consumption: and one employed in the foreign trade of consumption has the same advantage over an equal capital employed in the carrying trade. Upon equal, or only nearly equal profits, therefore, every individual naturally inclines to employ his capital in the manner in which it is likely to afford the greatest support to domestic industry, and to give revenue and employment to the greatest number of people of his own country.