An Econometric Model of the World Copper Industry

This paper discusses a complete model of the world copper economy. Supply equations for primary copper are estimated for four principal producing countries and the rest of the world; demand equations are estimated for the United States, Europe, Japan, and the Rest-of-World. Scrap supply equations are estimated for the U.S. and non-U.S. sectors as are price adjustment equations. The model is closed with a net input equation for the United States and various identities. The two separate copper markets (U.S. and non-U.S.) are converted by inputs, the generally free London Metal Exchange and scrap markets, and the price-setting behavior of U.S. producers. The copper market is found to be characterized by low short-run but very high long-run price elasticities, making for considerable sensitivity to exogenous forces. The model, fitted to 1948-1969 data, is used for forecasting and simulation experiments. Generally, short-run forecasts are good and longer-run forecasts are not very satisfactory. Perhaps the most interesting finding of the simulation is the prediction that Chilean output would be very sluggish even in the absence of nationalization and that Chilean revenues would be substantially increased were the Chilean government to increase domestic mine production and to allow world prices to adjust accordingly.