182
TABLE 19
AVERAGE ANNUAL RATES OF GROWTH OF COPPER,
IRON, AND STEEL PRODUCTION AND GROSS
NATIONAL PRODUCT, I9OO-I96O
(percent)
Average
Annual Rate of Growth
Period
Copper
Iron
Steel GNP
1900-1960
i.k
1.8
2.7 3.1
Source:
Table 18
and Long
Term Economic
Growth. 1860-1965, Part V, p. 107, Chart 17.
B.2 Imports and Exports of Copper
and Iron, 1900-1960
Copper production has been particularly influenced
by imports and exports. By the turn of the century between
one-third and one-half of the output of domestic copper
mines was being sent abroad, and net exports remained
relatively large until about 19^0. Since 1pUO the United
States has been a consistent importer of copper. In
contrast, neither imports nor exports of iron ore were
large relative to total output until the 1950s, after
which iron ore and steel imports increased substantially.
Net exports of pig iron have been inconsequential through
out the past century.