076 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
which expresses the fact that theoretical value of Yc is equal 
to its observed value, which is the same in all three cases (1), 
and it is this which generates the large differences noted. 
Nevertheless, very large values of n are of no more than 
speculative interest, and from the foregoing discussion, it may 
be considered that for n<7, the properties of the model studied 
are extremely close to those of the exponential model, whatever 
the value of w. 
It follows from this that if we can consider only the first 
few terms of the expansion of 3(0)e*® as a Taylor series, the 
general properties of the model will be very close to those of 
the exponential model. 
“ For the exponential model, we must put w=o in relation (540-1); 
or the para-exponential model, \=T. and for the mixed model &=u. 
11] Allais - pag. 280