Mineral resources appraisal and policy: Controversies,issues and the future

Political-economic events of the 1970s brought mineral resource appraisal to the focus of national policy. Estimates of and methodologies for mineral resources appraisal were scrutinized, revealing deficiencies in method and data and fostering considerable debate about the credibility of estimates and about preferred methodology. Since credibility can be increased through the acquisition of additional geoscience information, questions regarding methodology have more than one formulation and therefore more than one correct solution, depending upon the expected value of additional information and the conditional losses of relevant policy options. When existing information is meagre and the expected value of information is high, the optimum decision may be to defer all policy options until after the acquisition and analysis of- additional information. Decision theory offers an analytical framework that is sufficiently generalized to provide answers for highly varied circumstances of geoscience and resource information and policy issues. Our ability to perform any such analysis is limited by inaccuracies in both geologists' estimates of undiscovered mineral resources, and in economists' calculations of conditional losses of policy options for each of the relevant states of mineral resources.