rcumscribed area where influences that make for
change are very active and where obstacles are far smaller than they
are in the uncivilized regions.

_Essential Density of Population._--A perfectly static state requires,
not a perfectly equal distribution of population, but such a
distribution that there is no reason for further migrating. The power
of the soil to feed its inhabitants varies with its fertility. Where
the land is highly productive a dense population may live easily;
whereas on a sterile soil even a sparse population may find natural
resources too meager, and men may move to places which are more
thickly peopled and yet may gain by the change. Moreover, such
occupations as manufacturing and commerce require, of course, a far
larger population on a given area than does any form of agriculture.
Some regions are so undesirable as dwelling places that it takes an
exceptional economic reward to induce men to live there. The static
state is one in which, all these things being considered, there is no
reason for changing the place of one's abode. This implies more nearly
equal density per unit of natural resources than equal density per
unit of mere area. Inequality of advantage due to location is what is
leveled out, and doing this does not require nor permit that
population should everywhere be equally dense per square mile or per
acre.

_Effect of Differences of Occupation._--Regions given over to
agriculture naturally sustain more people than those devoted to
grazing, and those which are devoted to manufacturing sustain more
than either. In countries in which, as in Great Britain, manufacturing
is so disproportionately developed that products must be largely
exported, while food must be largely imported, given areas sustain
more inhabitants than they do in any agricultural or grazing region
and more than they do in any region where grazing and tillage, on the
one hand, and manufacturing, on the other, are well balanced. In mills
and shops auxiliary capital so abounds as to take the place of the
abundant land that is available in the other cases for making labor
fruitful, and in villages and cities labor does not overtax the
resources of the soil any more than it does on farms. It has area
enough to live and to work on and tools and materials enough to work
with. In a generally crowded country, the resort to commerce and
manufacturing relieves the pressure on the land, cities abound, and an
abundance of ca