Whereas a good resource estimate is the cornerstone of any project, the economic study is able to translate the in-situ resource into hypothetical economic value, and is therefore very important to investors, and financiers of any project. Three levels of studies are used in most cases: a Preliminary Economic Assessment (PEA), a Preliminary Feasibility Study (PFS) and a Feasibility Study (FS). A PEA is also called a Scoping study (Australia, Great Britain), and a FS can be named Bankable FS (BFS) or Definitive FS (DFS), although I have encountered other versions as well. Main difference between the three stages are the level of detail and accuracy/margin of error: a PEA has an accuracy of 25-30%, a PFS 20-25% and a FS 15%.
More coming soon.