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PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28

Since we have

(336-4) Ye=0,_ for 7-9:

4%.

(1

and ?- p is in general small, it follows that when an estimate
of 7, 1s available, it is possible to derive an order of magnitude
 of ©.
Then if we consider all those models for which

(336-5)

E=1

®, vw.

they differ from each other by the ovder of magnitude of the
parameter A, which is equal to unity in the exponential model.
Since we have

(336-6)

0) B(o)e 77°
?(0)- k¢(i-p)

4

and

b(o)=T

f?

it follows that as a first approximation, ¢(0) differs relatively
ttle from $3(0) for k=1.
It then follows that, at least as a first approximation, A is
greater than or smaller than unity according to whether the
amortization is more or less vapid than that corresponding to

" Relation (240-10)
Relation (223-7).
Relation (220-2)

Allais - pag. 178