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
Intergovernmental Council of Copper [Exporting Countries], CIPEC, 1967–1988

Prior to the rise of copper prices in late 2003 as part of the 2000s commodities boom various copper mining companies exhibited cartel-like behaviour. This consisted of announcements made in late 2001 for production cuts for 2002 which were carried out, and a repetition of similar announcements for 2003 in late 2002.