In the preceding chapter, economic welfare was taken broadly to consist of that group of s

atisfactions and dissatisfactions which can be brought into relation with a money measure. We have now to observe that this relation is not a direct one, but is mediated through desires and aversions. That is to say, the money that a person is prepared to offer for a thing measures directly, not the satisfaction he will get from the thing, but-the intensity of his desire for it. This distinction, obvious when stated, has been somewhat obscured for English-speaking students by the employment of the term utility - which naturally carries an association with satisfaction - to represent intensity of desire. Thus, when one thing is desired by a person more keenly than another, it is said to possess a greater utility to that person. Several writers have endeavored to get rid of the confusion which this use of words generates by substituting "utility" in the above sense for some other term, such as "desirability". The term "desiredness" seems, however, to be preferable, because, since it cannot be taken to have any ethical implication, it is less ambiguous. I shall myself employ that term.

Generally speaking, everybody prefers present pleasures or satisfactions of given magnitude to future pleasures or satisfactions of equal magnitude, even when the latter are perfectly certain to occur. But this preference for present pleasures does not - the idea is self-contradictory - imply that a present pleasure of given magnitude is any greater than a future pleasure of the same magnitude. It implies only that our telescopic faculty is defective, and that we, therefore, see future pleasures, as it were, on a diminished scale. That this is the right explanation is proved by the fact that exactly the same diminution is experienced when, apart from our tendency to forget ungratifying incidents, we contemplate the past.

Our analysis also suggests that economic welfare could be increased by some rightly chosen degree of differentiation in favor of saving. Nobody, of course, holds that the State should force its citizens to act as though so much objective wealth now and in the future were of exactly equal importance. In view of the uncertainty of productive developments, to say nothing of the mortality of nations and eventually of the human race itself, this would not, even in the extremest theory, be sound policy. But there is wide agreement that the State should protect the interests of the future in some degree against the effects of our irrational discounting and of our preference for ourselves over our descendants. The whole movement for "conservation" in the United States is based on this conviction.

It is the clear duty of Government, which is the trustee for unborn generations as well as for its present citizens, to watch over, and, if need be, by legislative enactment, to defend, the exhaustible natural resources of the country from rash and reckless spoliation.

Plainly, if we assume adequate competence on the part of governments, there is a valid case for some artificial encouragement to investment, particularly to investments the return from which will only begin to appear after the lapse of many years. It must, however, be remembered that, so long as people are left free to decide for themselves how much work they will do, interference, by fiscal or any other means , with the way they employ the resources that their work yields to them may react to diminish the aggregate amount of this work and so of those resources.

What does, according to the author, economic welfare consist of？

A．a general sense of contentment with any individual being part of a group

B．a basic duality or dichotomy between the amount of pleasures that one individual can experience and discontentment

C．the act of measuring the amount of gratifications and dissatisfactions with a measure of value

D．the relentless idea that people have to forfeit in expiation for their pleasures