pital averts the danger of a disastrous overcrowding.

_An approximately Static Distribution of Population._--The
apportionment of population among the different sections of a country
may be nearly normal, while migration may still go on from that
country as a whole to remote parts of the general area which we
include in our present study. There may be small reason for moving
from one part of Germany to another and large reason for going from
Germany to America. This larger movement occupies a long time, while
certain other adjustments may be made more quickly. Within Germany and
within the United States labor may be well apportioned among the
different occupations. There may be in each country about the right
comparative numbers of cotton spinners, iron workers, gardeners, wheat
raisers, etc.; or in other words, the distribution of labor among the
industrial groups may be approximately normal both within the one
country and within the other. It may further be true that the division
of occupations between the two countries in their entirety is about
what, in the conditions now prevailing, economic law calls for. There
are certain industries which now have their habitats in Germany and
certain others that have their habitats in the United States, and this
arrangement is partly due to the comparative density of the two
populations. Because there are so many persons per square mile of land
in Germany there is there a certain preponderance of manufacturing,
and there are in America less manufacturing and relatively more
agriculture. In that remote time when the relative density of the two
populations shall become static, America will have reason to increase
the comparative amount of the manufacturing and thus put herself in
this particular more nearly on a plane with Germany. This occupation
has its normal abode in regions of comparatively dense population, and
a gain in comparative density means an increase in the amount of
productive energy devoted to it. The place for the mill is where the
land is crowded, and the better place for the work of tillage is where
it is not so.[2]

[2] It will appear that manufacturing reacts on the density
of population, first, by retarding emigration from the
thickly populated country as a whole; and secondly, by
causing local movements within the country, whereby cities
and villages grow, and relieve what would otherwise be an
excess of labor in agricultural regio