Copper cartels

Since 1870, there have been several formal attempts to restrict the copper output and raise, in this form, its price.

This is a list of copper cartels in the 20th century:
 * Copper Export Association, CEA, 1918–1923
 * Copper Exporters, Inc., CEI, 1926–1932
 * International Copper Cartel, ICC, 1935–1939 (created by the World Copper Agreement)
 * Intergovernmental Council of Copper Exporting Countries, CIPEC, 1967–1988