Production statistics for pig-iron, copper, lead, aluminum, and petroleum plotted over a long period for single years consistently show downward offsets, overall, as strong effects of wars and depressions. World production of these commodities is steadily rising, but that of the United States is leveling off, particularly when production per capita is plotted. World production curves for petroleum, pig iron, and copper are sufficiently well established to have value in forecasting.

First Page Preview

First page PDF preview
You do not currently have access to this article.