The Wealth of Nations by Part 4 Chapter 5 Page 4

own interest would soon oblige him to employ his stock in another way, or to find out a trade in which the price of the goods would replace to him, with the ordinary profit, the capital employment in sending them to market. The effect of bounties, like that of all the other expedients of the mercantile system, can only be to force the trade of a country into a channel much less advantageous than that in which it would naturally run of its own accord.

The ingenious and well-informed author of the tracts upon the corn trade has shown very clearly that, since the bounty upon the exportation of corn was first established, the price of the corn exported, valued moderately enough, has exceeded that of the corn imported, valued very high, by a much greater sum than the amount of the whole bounties which have been paid during that period.