Corn brings out the best in Adam Smith. These are all observations about corn, taken from Book IV, Chapter 5 of The Wealth of Nations
On gouging and price controls to prevent it:
When the government, in order to remedy the inconveniences of a dearth, orders all the dealers to sell their corn at what it supposes a reasonable price, it either hinders them from bringing it to market, which may sometimes produce a famine even in the beginning of the season; or if they bring it thither, it enables the people, and thereby encourages them to consume it so fast as must necessarily produce a famine before the end of the season. The unlimited, unrestrained freedom of the corn trade, as it is the only effectual preventative of the miseries of a famine, so it is the best palliative of the inconveniences of a dearth; for the inconveniences of a real scarcity cannot be remedied, they can only be palliated. No trade deserves more the full protection of the law, and no trade requires it so much, because no trade is so much exposed to popular odium.
But if a merchant ever buys up corn, either going to a particular market or in a particular market, in order to sell it again soon after in the same market, it must be because he judges that the market cannot be so liberally supplied through the whole season as upon that particular occasion, and that the price, therefore, must soon rise. If he judges wrong in this, and if the price does not rise, he not only loses the whole profit of the stock which he employs in this manner, but a part of the stock itself, by the expence and loss which necessarily attend the storing and keeping of corn. He hurts himself, therefore, much more essentially than he can hurt even the particular people whom he may hinder from supplying themselves upon that particular market day, because they may afterwards supply themselves just as cheap upon any other market day. If he judges right, instead of hurting the great body of the people, he renders them a most important service. By making them feel the inconveniencies of a dearth somewhat earlier than they otherwise might do, he prevents their feeling them afterwards so severely as they certainly would do, if the cheapness of price encouraged them to consume faster than suited the real scarcity of the season. When the scarcity is real, the best thing that can be done for the people is to divide the inconveniencies of it as equally as possible through all the different months, and weeks, and days of the year. The interest of the corn merchant makes him study to do this as exactly as he can: and as no other person can have either the same interest, or the same knowledge, or the same abilities to do it so exactly as he, this most important operation of commerce ought to be trusted entirely to him; or, in other words, the corn trade, so far at least as concerns the supply of the home market, ought to be left perfectly free.
On political economy and the myth of the rational voter:
The laws concerning corn may every-where be compared to the laws concerning religion. The people feel themselves so much interested in what relates either of their subsistence in this life, or to their happiness in a life to come, that government must yield to their prejudices, and, in order to preserve the public tranquillity, establish that system which they approve of. It is upon this account, perhaps, that we so seldom find a reasonable system established with regard to either of those two capital objects.