HKB
Consumable commodities are either necessaries or luxuries.
By necessaries I understand, not only the commodities which are indispensibly necessary for the support of life, but whatever the custom of the country renders it indecent for creditable people, even of the lowest order, to be without. A linen shirt, for example, is, strictly speaking, not a necessary of life. The Greeks and Romans lived, I suppose, very comfortably, though they had no linen. But in the present times, through the greater part of Europe, a creditable day-labourer would be ashamed to appear in public without a linen shirt, the want of which would be supposed to denote that disgraceful degree of poverty, which, it is presumed, nobody can well fall into without extreme bad conduct. Custom, in the same manner, has rendered leather shoes a necessary of life in England. The poorest creditable person, of either sex, would be ashamed to appear in public without them. In Scotland, custom has rendered them a necessary of life to the lowest order of men; but not to the same order of women, who may, without any discredit, walk about barefooted. In France, they are necessaries neither to men nor to women; the lowest rank of both sexes appearing there publicly, without any discredit, sometimes in wooden shoes, and sometimes barefooted. Under necessaries, therefore, I comprehend, not only those things which nature, but those things which the established rules of decency have rendered necessary to the lowest rank of people. All other things I call luxuries, without meaning, by this appellation, to throw the smallest degree of reproach upon the temperate use of them. Beer and ale, for example, in Great Britain, and wine, even in the wine countries, I call luxuries. A man of any rank may, without any reproach, abstain totally from tasting such liquors. Nature does not render them necessary for the support of life; and custom nowhere renders it indecent to live without them.
As the wages of labour are everywhere regulated, partly by the demand for it, and partly by the average price of the necessary articles of subsistence; whatever raises this average price must necessarily raise those wages; so that the labourer may still be able to purchase that quantity of those necessary articles which the state of the demand for labour, whether increasing, stationary, or declining, requires that he should have. {See book i.chap. 8} A tax upon those articles necessarily raises their price somewhat higher than the amount of the tax, because the dealer, who advances the tax, must generally get it back, with a profit. Such a tax must, therefore, occasion a rise in the wages of labour, proportionable to this rise of price.
It is thus that a tax upon the necessaries of life operates exactly in the same manner as a direct tax upon the wages of labour. The labourer, though he may pay it out of his hand, cannot, for any considerable time at least, be properly said even to advance it. It must always, in the long-run, be advanced to him by his immediate employer, in the advanced state of wages. His employer, if he is a manufacturer, will charge upon the price of his goods the rise of wages, together with a profit, so that the final payment of the tax, together with this overcharge, will fall upon the consumer. If his employer is a farmer, the final payment, together with a like overcharge, will fall upon the rent of the landlord.