52 
POLITICAL ECONOMY 
For the twelve apples a week I give Is. a 
week, but rather than do without any apples 
I would give for the twelve Is. 9d. My 
consumer’s surplus reckoned in money is, 
therefore, ninepence on the apples. For 
convenience let us call this expression of the 
surplus in terms of money monetary con 
sumer’s surplus. 
To make the notion with which we have 
been dealing of substantial practical value, we 
have to conceive of an aggregate monetary 
surplus, with reference to any commodity, 
which is made up of the surpluses of a number 
of different individuals. There is no difficulty 
in doing this, as it is perfectly possible to add 
together sums of money which belong to 
different people, though it is not possible to 
conceive of the addition of the things (prefer 
ences) to which these sums of money refer. 
After performing the operation of adding 
together consumer’s surpluses in money, 
we must not, however, fall into the error 
of thinking that £1 worth of one person’s 
consumer’s surplus is the same thing as £l 
worth of another person’s consumer’s surplus. 
But this reservation notwithstanding, the 
conception of a consumers’ (in the plural, 
observe) monetary surplus is of value because 
it is not unreasonable to suppose that, other