18-Geol-B8 Resource Economics & Valuation · May 2016
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — May 2016 — 04-Geol-B8, Resource Economics and Valuation. Three-hour, open-book exam; any non-communicating calculator permitted. Six questions are printed; the exam's own cover notes state that only the first four questions in the answer book are marked, and each of the six is of equal value (25 marks) — all six are answered here as a complete study resource. Most questions require mathematical solutions, and clarity and organization of the steps involved are explicitly graded.
Reference texts: Torries, Evaluating Mineral Projects: Applications and Misconceptions (SME, 1998) — discounted cash flow valuation of mine projects, net smelter return economics, royalty valuation, and cut-off grade theory; Rudenno, The Mining Valuation Handbook, 4th ed. (Wrightbooks, 2012) — comparable-transaction and appraised-value (Kilburn) methods, copper-equivalent grade, and resource/reserve-stage valuation; EGBC Geoscience Professional Practice Guidelines for assumption-disclosure conventions on open-book calculations.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
A mineral project's supply pipeline runs from an exploration target (a geoscientific concept with no drilling-confirmed resource), through inferred, indicated and measured mineral resources of progressively increasing confidence, to a mineral reserve demonstrated economically viable at pre-feasibility or feasibility level. No single valuation method is appropriate across that whole pipeline, because the underlying data needed by the more rigorous methods simply does not exist at the earlier stages; the methods below are applied in a roughly ascending order of data requirement, and more than one is often triangulated together at any given stage.
| Method | Data required / earliest applicable stage | Strength | Weakness |
|---|---|---|---|
| Cost-based / appraised value (e.g. Kilburn geological method) | Exploration target – needs only cumulative exploration spend and a geological favourability assessment | Usable before any resource exists; grounded in verifiable historical expenditure | Prospectivity multiplier is subjective; disconnected from commodity price and market sentiment |
| Comparable transactions ($/oz or $/lb of contained/in-situ resource) | Inferred resource onward – needs a defined resource and an active comparable-deal market | Reflects real, current market sentiment and risk pricing | Requires enough truly comparable arm's-length deals (commodity, stage, jurisdiction); thin or stale in quiet markets |
| Option-pricing (real options) | Any stage, most differentiating pre-resource where DCF cannot yet be built | Rigorously captures the asymmetric value of flexibility (develop only if favourable) | Complex, highly sensitive to the assumed volatility input, hard for a lender or regulator to audit |
| Market capitalization (public single-asset company) | Any stage, only once the project is held by a publicly traded company | A direct, continuously observable market valuation | Only isolates the project's value net of cash/other assets; noisy, sentiment-driven for small-cap issuers |
| Discounted cash flow (DCF/NPV) | Indicated/measured resource with at least a Preliminary Economic Assessment; primary method from pre-feasibility onward | Most rigorous, transparent and widely accepted once a mine plan and cost/price forecast exist | Not usable pre-resource; highly sensitive to price and discount-rate assumptions; a single static scenario understates flexibility value |
At the exploration-target stage, with no drilling-confirmed resource, only the cost-based appraised-value approach is really workable: it multiplies verifiable historical (and sometimes budgeted future) exploration expenditure by a prospectivity enhancement multiplier reflecting how favourable the geological setting appears relative to known deposit models, typically in the range of roughly 0.5–3×. Its strength is that it needs no resource estimate at all; its weakness is that the multiplier is a geologist's professional judgment rather than a market-observed number, so it says little about whether the market would currently pay for that geological promise. As drilling advances a project into an inferred, then indicated, then measured resource, comparable-transaction pricing on a per-ounce or per-pound basis of contained or in-situ metal becomes usable and increasingly reliable, because a defined (if still uncertain) resource size now exists to normalize transaction prices against; its central weakness is data scarcity — there may simply not be enough recent, truly comparable deals in the same commodity, jurisdiction and development stage to anchor a defensible multiple, particularly in a quiet part of the commodity cycle. The real-options approach can in principle be applied at any point in the pipeline, since it only requires an assumption about price volatility and a defined decision point (develop or walk away), and it is most valuable precisely where DCF cannot yet be built — it captures the fact that an undeveloped deposit is worth more than its "expected case" NPV alone because management retains the flexibility not to develop it if conditions turn unfavourable — but this rigour comes at the cost of a complex, assumption-heavy model that is difficult for a lender, regulator or unsophisticated investor to independently verify. Once a project reaches indicated or measured resource status supported by at least a Preliminary Economic Assessment, and especially once it reaches pre-feasibility or feasibility with a defined mine plan, cost estimate and price forecast, discounted cash flow becomes both usable and the industry-standard primary method, because the underlying data (tonnage, grade, recoveries, capital and operating costs, mine schedule) now exists in sufficient detail to forecast an actual cash-flow stream; its weakness even at this stage is that it collapses a genuinely uncertain future into one static scenario and remains highly sensitive to the assumed long-term price and discount rate, which is why practitioners routinely triangulate a DCF value against comparable transactions and, where the company is publicly listed, against its market capitalization as cross-checks on any single method's blind spots.
