32 THE SHADOW OF THE WORLD'S FUTURE
season for them, must not be less than a certain
minimum. Finally, the crop produced must at least
pay for the labour of cultivation. In connection with
this last condition, however, popular ideas as to what
constitutes a “ reasonable standard-of-living ” affect
the issue. This covers not merely food, according
to some “dietary standard,” but clothing, housing,
education and the whole paraphernalia of social life.
These are the governing conditions previously referred
to.
In this connection it may be mentioned that although
the American “ dietary standard ” is a cheap balanced
ratio consisting largely of vegetable products, the
energy-value of which is 3500 calories per diem, it
cannot be regarded as in any way representing a worldaverage.
 The standards of the Chinese, Japanese and
Hindu masses are, of course, much lower than this.
Even that of Europe is only about 3000 calories per
diem.
In regard to living-standards, too, it may further be
said that if, as appears to be already beginning, the
multitudes of the East should westernise their conceptions
 as to what constitutes a reasonable standard,
the population-problem is at once raised to a plane of
greater difficulty. On the other hand, if western races
ever abandon both their present love of what may
seem to some inordinate luxury, and all useless complication
 of the paraphernalia of social life, it is certain
that the population difficulty, for a time at least, will
diminish. It is also temporarily diminished by every
betterment in the organisation of human effort in
production and distribution, and by success in insuring
against the vicissitudes of Nature, which often, in
quite a little while, wreck the effect of long periods of
effort. Some of the countries considered are subject
to repeated periods of calamity.
Turning now to the light which American research