1186 PONTITICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - Z° 
an underdeveloped country. I see a great danger here. On the 
other hand, there are very important questions, some of which have 
been raised by Mr. JoHNSON, about how the econometricians in 
advanced countries can help the underdeveloped countries. This is 
a question of vital importance, not only for the underdeveloped 
countries, but also in the enlightened self-interest of the advanced 
countries. 
KOOPMANS 
A brief question — in these elasticity estimates, does food include 
the tin can and the tip to the waiter, or not? 
JOHNSON 
What I talked about was food at the farm-gate level 
KOOPMANS 
The other question is about the need for these projections — so 
to say the marginal productivity of improvements in the accuracy 
of the projection. What decisions do depend very much on having 
accurate projections and what harm is done if projections are inac- 
curate? If no great harm is done it is a nice purpose just the same 
to improve accuracy, but it wouldn’t rank- with as high a priority 
in econometric work 
JOHNSON 
I think this is a very pertinent and relevant question and I 
would try to answer it in terms of the difference in plans in the 
planned and the essentially free-market countries. I think that in- 
"167 Johnson - pag. 46