The minerals availability program of the Bureau of Mines conducts cost evaluations of current and potential mineral operations in the United States and foreign countries. The international mining cost indexation system (imci) allows data of different time periods within a country to be updated to a common base year for analytical purposes. The imci comprises 12 factor cost indexes and an exchange rate series for 96 market economy countries, denominated in both local and U.S. currency. The imci for each country contains 12 time series indexes that measure the average annual rate of change in the cost of factor inputs to the mining industry within that country. Mining industry factor cost indexes include wages, plant and equipment, construction and mining materials, power and transportation, and other measures considered to comprise the majority of capital and operating costs. Cost data or proxies are collected in local currency. Index series within each country are constructed separately and indexed on a 1975 base year. The local currency index is converted to a U.S.-dollar-based currency index using an exchange ratio.