A STATISTICAL METHOD FOR MEASURING ‘MARGINAL UTILITY’ 165
market prices and index numbers of these. Let us suppose Fj,
the food price level in Oddland, to be a third greater than F.
(=1), the food price level in Evenland, or F;—$1.3314 per
pound.
That 1s, we divide W;F;=1 by F;—1.3314 and obtain
W,=.75 of a “wantab.”
We have calculated W,, the want-for-one-more dollar of the
family called Case 1. This calculation has been made on the
basis of data relating to food alone; but, in accordance with
well known economic theory, we assume that the want-for-onemore
 dollar of a given family is the same as the want-for-onemore
 dollar’s worth of food, clothing, shelter or any other item
of expenditure.
The above process, or chain of calculations, by which W; is
found from W, may be tabulated as follows:
Given W; = 1 wantab
Given F; = $1.00
Multiplying, we get WF: = 1 wanta.
This is same as WF, = 1 wantat
Given F, = $1.333
Dividing, we get W; = .75 of a wantab

Want-for-one-more
dollar in Case 2.
Price Index of Food,
Case 2.
Want-for-one-more
pound of food, Case 2.
Want-for-one-more
pound of food, Case 1.
: Price Index of Food,
Case 1.
Want-for-one-more
dollar, Case 1.
We have now found W; from W.. We can next find Wj from
W. analogously. Briefly:
Given W. = 1 want~h
PR- pie
W.-R,

= Want-for-one-more
dollar, Case 2.
Price Index of Rent,
Case 2.
Want-for-one-more
square foot of housing,
Case 2.
Want-for-one-more
square foot of housing,
Case 3.
Price Index of Rent,
Case 3.
= Want-for-one-more
dollar, Case 3.

1 wants

Same as

W3R; = 1 wantab

Given

Dividing.

Wi: = .331 of a wantab

wd
ta

We have now calculated W3, the want-for-one-more dollar of
the family called Case 3. This calculation was made from house
rent data, but of course represents the want-for-one-more dollar
expended for anything else.