SEMAINE D ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 
100] 
artificially low level which did not correspond to the general eco- 
nomic situation. Thus, the rate of interest on investment was cer- 
tainly much higher than the rate of interest on bonds which I have 
considered (Econometrica’s paper, p. 714). The conclusion is 
that the bond rate is not a good indicator of the pure rate of 
interest. 
Thus, FISHER's objection might be valid if, and only il, we 
know the right value of i. But we don’t know the right valu. of 
and the errors on i can explain the greater range of variation of © 
In response to Professor FISHER, I must again stress that I did 
not say that the facts prove the validity of my model, but only 
that my model is in agreement with every known fact (§ 337 of my 
paper), and nothing else. 
HAAVELMO 
I think we ought to distinguish clearly between what you say 
about the shape of the production function and what you say ab:ut 
the capital-output ratio, because the latter does not depend un ‘ie 
production function alone. It depends on the whole pattern of 
economic behaviour, that is, on manv other things besides the pro- 
duction function 
MALINVAUD 
In his very stimulating contribution, Professor ALLAIS uses . 
model of capital theory in which primary inputs are introduced 
continuously and « mature » in final outputs after some time, the 
delay, between input and output being subject to a fixed or varying 
distribution. Such a model, that may be traced back to JEvons, 
is rather neglected today. I am glad to take this opportunity to 
express the view that we should probably use that model more 
than we in fact do. It has rendered great services to capital theory 
11] Allais - pag. 305