CONCLUSIONS AS TO POPULATION INCREASE 121 
America is carrying only 39, being told also by certain 
special and able students that it can never carry more 
than 66 to the square mile, one realises how superficial 
are some of the studies of the world’s possibilities. 
The data do not yet exist by means of which a really 
exhaustive estimate can be made of the world’s popula- 
tion-limits, as things are at present, nor as they are 
likely to be. But we do know enough to affirm with 
confidence, that the fear that a country with immense 
resources can carry only 66 to the square mile is 
created by too narrow a view of the problem in hand. 
No sufficient account has been taken of the standard- 
of-living assumed to be essential, nor of the fact that 
the theory leading to this estimate is based upon 
merely temporary, undeveloped and unessential con- 
ditions. It may of course be true that the easy state 
of things in any new country must pass as the world’s 
peoples multiply, and that the standards existing must 
perforce change. If they do change in the direction 
of less luxury, then the estimate of 66 people to the 
square mile goes by the board. 
Even should our estimates of the limits of popula- 
tion be too modest, it still remains true that mankind 
is profligate in the use of such of Nature’s materials 
as are immediately at his disposal, and he is apply- 
ing them, and the food-stuffs likely to be available, 
recklessly. For this reason Man will certainly be 
pulled up in the near future, and the Shadow of 
his future remains in being. What we said in our 
report on the Australian Census of 1911 remains true. 
Our words were *— 
“The limits of human expansion are much nearer 
than popular opinion imagines; the difficulty of future 
food supplies will soon be of the gravest character; 
the exhaustion of sources of energy necessary for any 
notable increase of population or advance in the