The monthly spot prices in the international tin and copper and U.S. domestic lead markets are modeled based on the

supply of storage

concept. In all cases the lag-1 natural log
S/C (stocks/consumption) was highly important in the final fitted equation. For copper and lead, trend directions in the U.S. Index of Leading Economic Indicators modified the
S/C dependency. Disaggregation of the tin stocks showed the special model sensitivity to the level of the ITC buffer stock. The underlying econometric models are used to estimate the price intervention effects of international political-economic crises, and commodity producer cartel actions.