It- will, be noted that the process' can be described up to 
this point without any reference to. income. We. may-regard the 
states of the system represented by the elements of the matrix.' 
as "graces or ,r age" -'possibly carreer, age or age in earning 
life,, although in conformity with Champernowne we referred to. 
them as income classes. . ' .■ ..f - ; 
We have now to define the inccme.in relation to the class 
intervals of the matrix:. The lower limit of class 1 is 
taken to he the minimum'income. We may choose the income 
units such that the minimum income is unity, i.e. on the 
logarithmic scale it is zero. The income y^ at the lower 
limit of successive income classes K is' defined hy 
l 
y 
or In y K = Kh 
1) 
where h is the size of the class interval on the log scale '. 
Ik - e 
kh 
C 
The difS-culties arising from the discrete representation of 
a continuous income variable in the matrix do not concern 
us here. See £/qJ p. 62. TZe-j 
r cL.- 
•4 
& 
</£ Ld 
/ w 
/Cl- *■'. 't 
'nr 
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