This report presents economic principles and applications as they pertain to the U.S. Geological Survey’s U.S. Coal Resources and Reserves Assessment Project. This report compares commercial and governmental applications of economic principles and evaluation techniques. Common practices are described for evaluating the commercial investment potential of coal properties and calculating the government reserve potential of major U.S. coal basins. This report discusses economic principles that are applicable to typical mining feasibility studies as well as those categories and cost items that are often misused.