ABSTRACT
The shifts in the relative importance of different countries and different states within the United States are associated with a substantial movement within a relatively stable size distribution of copper mining companies. Two important factors that limit the exercise of monopoly power do not show up in the measures of concentration in the production of copper used in this study. They are the production of copper from scrap and the competition provided by aluminum for a substantial part of the demand. A part of the scrap component of total supply, that is, a part of new scrap, is controlled by the producers of newly mined copper through fabricating subsidiaries. But the fact still deserves emphasis that the measures of concentration used here do not reflect an important independent component of the supply of copper, or, alternatively, do not reflect a factor serving to increase the elasticity of demand facing the producers of newly mined copper.
