upon the native birthrate, leaving the immigration nearly a net
addition to population. It does not seem possible to believe that
if there had been no immigration, our native population, rapidly
advancing in average wealth, wages, and general education, would have
continued with an unchecked birthrate, and would have filled all the
places taken by immigrants. And no believer in the displacement
theory has ever ventured to claim, as the argument requires, that if
immigration were now stopped, the birthrate would again return to the
old standard of 1820, or would cease to decrease somewhat. Especially
of late, since the rate of increase of the native population has
become much less, is the effect of continuing immigration apparent.
In the decade of 1900-1910 the total population increased 16,000,000,
while nearly 9,000,000 immigrants arrived. Of the remaining increase,
3,000,000 consisted of children born of foreign parents. That leaves
three or at the most four million (4,000,000) increase attributable to
the native stock, white and negro combined.

Sec. 12. #Earlier and recent effects of immigration upon wages.# Let us
now correlate the principle of decreasing returns and the facts as to
the exploitation of our natural resources[10] with the growth of
our population, on the assumption that immigration has been a net
contribution to our numbers. While the vast frontier was open to
settlement, the growth of population could not fail to be looked
upon as a blessing, even tho somewhat mixed with political evils,
immorality, and pauperism. Beginning in colonial times, the policy of
"the open door" to immigrants came thus to be deemed the traditional,
patriotic American policy. Yet there is grave reason to believe that
the rate of growth in the nineteenth century was wastefully rapid and
that a slower and sounder growth might have been better.[11] However,
this rapid growth was largely extensive, spreading over wider areas,
and was consistent with a pretty steady rise of real wages in America
until about 1895,[12] the level continuing higher than that of Europe
despite the contemporaneous rise of wages there. Much of this general
rise is undoubtedly attributable to the adoption of better tools,
machinery, and industrial processes, the more so as inventions and
new methods have rapidly become free goods.[13] The beneficial
improvements long cooperated with the rapid exploitation of rich
resources to raise real wages, and then