The articles or forms of consumption to which the consumer clings with the greatest tenacity are commonly the so-called necessaries of life, or the subsistence minimum.

The subsistence minimum is of course not a rigidly determined allowance of goods, definite and invariable in kind and quantity; but for the purpose in hand it may be taken to comprise a certain, more or less definite, aggregate of consumption required for the maintenance of life.

This minimum, it may be assumed, is ordinarily given up last in case of a progressive retrenchment of expenditure.

That is to say, in a general way, the most ancient and ingrained of the habits which govern the individual's life--those habits that touch his existence as an organism--are the most persistent and imperative.

Beyond these come the higher wants--later-formed habits of the individual or the race--in a somewhat irregular and by no means invariable gradation.