23 
understand and interpret the empirical joint distributions 
of income and wealth. For this purpose one would no doubt 
require data which are more conveniently arranged than the 
published material used above, and for this reason alone 
it would go beyond the modest scope of this paper. 
Footnotes. 
1 The difficulties arising from the discrete 
representation of a continuous income variable 
(Cramer,1969,p.62)in the matrix need not concern us 
here.They do not exist since we relate the classes of the 
matrix to rank in a hierarchy. 
2 Champernowne apparently did not know Yule's paper. It 
was Simon's merit to have brought it to the attention of 
economists.Unfortunately he used it in a form which 
obscured its essence which is the interplay of two 
exponential,or geometrical,distributions resulting from 
two stochastic processes. 
A very different approach to the Pareto law has been 
proposed by D.Sahal (1978) who connected it with the 
progress function and with the allometric law (the 
relation between the growth rates of different parts of an 
organism).