The issue of interest has to do especially in the way in which goods and services are estimated by the individual; not only in terms of how they satisfy needs, but also their value over time. In this way, so important are the goods in the present, that it is also necessary to consider that those goods and services are more important in the future, since the survival of the individual depends on it.
In relation to this, Carl Menger argues that:
"To the extent that the maintenance of our lives depends on the satisfaction of our needs, guaranteeing the satisfaction of earlier needs must necessarily precede attention to later ones. And even where not our lives but merely our continuing well-being (above all our health) is dependent on command of a quantity of goods, the attainment of well-being in a nearer period is, as a rule, a prerequisite of well-being in a later period. Command of the means for the maintenance of our well-being at some distant time avails us little if poverty and distress have already undermined our health or stunted our development in an earlier period."
Carl Menger, Principles of Economics (New York: New York University Press, 1976), p. 153.