Source data for estimation of additions to mineral and energy resources are from Geoscience Australia which publishes annual estimates of economically demonstrated resources (EDR). Information on additions are required to estimate the total in situ quantity of each mineral type available for extraction.
To estimate economic rents, information on domestic production, mineral prices and production costs are required. The data on domestic production of mineral resources is sourced from Geoscience Australia's Australia's Identified Mineral Resources (AIMR) and Oil and Gas Resources of Australia (OGRA). Mineral prices are derived from a number of publicly available resources, including the Australian Financial Review and the Bureau of Resources and Energy Economics' (BREE) quarterly publication Resources and Energy Statistics. The data on production costs is provided by a private consulting firm and is derived using company reported financial information from a sample set of mines and industry trends.
Data on normal returns to produced capital are derived by the ABS using national accounts capital stock estimates, an appropriate discount rate and extraction costs. This data is used to estimate the returns to produced and non-produced asset.
To estimate NPV, the discount rate chosen is based on the Reserve Bank of Australia’s (RBA) large business variable lending rate as published in Statistical Table F5 Indicator Lending Rates. Mine lives are estimated as the total stock of each mineral type available divided by the quantity extracted in a given year.