DISCUSSION 
grain equivalent, or roughly Colin Clark’s figure. To this, how- 
ever, must be added—and I think Clark omitted to do this— 
losses in extraction which amount to about 20 per cent, and 
losses due to non-food use, such as seeds, in manufactures, and 
also storage losses, which together account for about a further 
15 per cent. Therefore Clark underestimates the grain equiva- 
lent at production level—and this is the important point—by 
between one-fifth and one-third. Thus his estimate is 250 kilo- 
grams as against 300/350 kilograms in practice. Now this is a 
considerable discrepancy for the underdeveloped countries 
where agriculture is difficult; and, most important, Clark’s 
figure makes no allowance for minerals and vitamins which he 
rightly holds to be essential. 
The second factual error is the statement that a person’s 
minimum requirements for a year can be grown by any good 
farmer on 600 square metres. The present world output is 
about 500 kilograms of grain equivalent per hectare of agricul- 
tural land. Now if we assume my minimum figure of 300 
kilograms to be necessary, we should require on a world basis 
three-fifths of a hectare or 6,000 square metres. The world 
average yield per hectare would therefore have to be increased 
ten-fold above the present level in order to reach 300 kilograms 
of grain at production level from 600 square metres. Pheno- 
menal increases can be obtained in agriculture in certain 
areas, but a ten-fold increase is surely too much to expect 
universally in the foreseeable future and certainly needs 
more emphasis than saying that “it can be done by any good 
farmer”’. 
The third point is that even in the Far East we are already 
producing 340 kilograms of net grain equivalent per person 
per year, which corresponds to about 450 kilograms at the 
production level. Thus nearly double Clark’s figure is already 
available in the Far East, and yet there is substantial malnutri- 
tion as well as under-nutrition in this region today, which the 
existing rate of production is apparently incapable of meeting. 
I would prefer to leave it to Brock and to Trowell to discuss 
the general question of the extent of malnutrition because they 
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