e she separates out and considers by
itself the extra utility of an additional pound. She may buy more,
because she has formed the habit of spending so much money on sugar;
and now that the price has fallen, the same amount of money will
enable her to buy more pounds. Or, perhaps, she may be moved by
instinctive and irresistible attraction to buy more of a thing when it
is cheaper, similar to that which inspires so many people to face with
ardor the horrors of a bargain sale. In any case the fine calculations
I have imagined convey a fantastic picture of her state of mind. And
how much more fantastic, the critic may continue, of the state of mind
in which things of a different kind are bought by less careful
people. When, for instance, one of us happy-go-lucky males (more
liberally supplied, perhaps, than the housewife with the necessary
cash), decides to buy a motor bicycle, or to replenish his stock of
collars or ties, does the above analysis bear any resemblance to the
actual facts? In the case of the motor bicycle, the purchaser may,
indeed, weigh the price fairly carefully against the pleasure and
benefit, though contrariwise he may be a rich enough gentleman hardly
to bother about this. But, one motor bicycle is as much as he is at
all likely to buy, and what becomes, then, of the distinction between
total and marginal utility? In the case of the ties and collars, the
vagueness of many of us about the price will be extreme. We probably
have been uneasily conscious for some time of an inconvenient shortage
of these troublesome articles and eventually will go off (or perhaps
will be sent off with ignominy) to the nearest suitable shop to make
good the deficiency. How can we speak here with a straight face of the
relation between marginal utility and price?

These are very pertinent criticisms; but they do not make nearly as
much nonsense of the notion of marginal utility as may seem at
first. The last point, indeed, serves rather to give it a fresh aspect
of much significance. Those of us who do not bother about the price we
pay for our ties and collars owe a debt of gratitude, of which we are
insufficiently conscious, to the more careful people who do; as well
as to the custom which prevails in shops in Western countries (as
distinct from the bazaars of the East) of charging as a rule a uniform
price to all customers. If _we_ were the only people who bought these
things, an enterprising salesman would be able to ch