782 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
The Expression for Re 
224 
From (122-1), we derive 
(224-1) R,(#)=R, (ef ep (0) do 
= Be) 
“Ro(t)/ For de 
so that 
(224-2) 
R, (2) 
Rolt) = Sra 
National Income 
225. 
From relation (124-3) we have 
| 
€ 
225-1) 
F 
I 
11] Allais - pag. 86