CHAPTER XVII 
SUMMARY OF PART III (CHAPTERS XI-XVI) REPRESENTED 
BY DIAGRAMS 
§1 
We have finished our study of the relations between 
capital-value and income-value and may .now pause to 
summarize them briefly. At the beginning of Part III it 
was stated that the income from capital wealth consists 
of whatever service it performs for man; that capital and 
income may each be measured either in specific quantities 
of their respective units, or in value; and that consequently 
there are four ratios between income and capital; namely, 
(1) the physical productivity of capital, (2) the value pro- 
ductivity, (3) the physical return, and (4) the value- 
return. Our special theme has been the value-return, — 
the relation between income-value and capital-value. 
We saw that the value of capital wealth is the discounted 
value of its expected income. The relation between the 
value of the income and the value of the capital was indi- 
cated by diagrams. Income Was represented by a series 
of vertical lines as in Figure 13 (a, a’, 0 ' a"), the hori- 
zontal distances between them representing intervals of 
time. It was then found possible to represent the capital- 
value of this income in anticipation, on the assumption 
that the income could be relied upon with certainty. 
This representation gave the capital curve, — a broken or 
toothed curve AB. In this curve, each vertical drop 1s 
equal to the corresponding income item shown below it, 
and the intervening points are connected by discount 
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