Geological supply and economic demand: The unresolved equation

Whereas the ultimate world supply of minerals is controlled by geological factors, the actual supply at any particular time is controlled by economic factors. Mineral production is a function of investment in exploration, mining, and processing - and research in these fields. Given the long lead time between a decision to explore and actual production from any deposit found, the increasing difficulty of finding deposits in the well prospected parts of the world, the political barriers to exploration in the less developed countries, the energy barriers to mining and processing ever lower grade ores, and the lengthy time required to develop new exploration, extraction, and processing techniques, adjustments in supply in response to changes in demand cannot be assumed to be automatic.