4.	Critical accounting estimates and judgements

The preparation of financial statements in conformity with IFRS requires management to make judgements, estimates and assumptions that affect the application of accounting policies and the reported amounts of assets, liabilities, income and expenses. Actual results may differ from these estimates.

Estimates and underlying assumptions are reviewed at each period end. Revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.

Significant areas requiring the use of management estimates include assumptions and estimates relating to determining defined proven and probable reserves, value beyond proven and probable reserves, fair values for purposes of purchase price allocations for business acquisitions, asset impairment analyses, asset retirement obligations, share-based payments and warrants, pension benefits, valuation of deferred income tax assets, the provision for income tax liabilities, deferred income taxes and assessing and evaluating contingencies.

Actual results could differ from these estimates. Outlined below are some of the areas which require management to make significant estimates and assumptions in determining carrying values.

Purchase price allocation

Business combinations require estimates to be made at the date of acquisition in relation to determining asset and liability fair values and the allocation of the purchase consideration over the fair value of the assets and liabilities.

In respect of mining company acquisitions purchase consideration is typically allocated to the mineral reserves and resources being acquired. The estimate of reserves and resources is subject to assumptions relating to life of the mine and may change when new information becomes available. Changes in reserves and resources as a result of factors such as production costs, recovery rates, grade or reserves or commodity prices could impact depreciation rates, asset carrying values and environmental and restoration provisions. Changes in assumptions over long-term commodity prices, market demand and supply, and economic and regulatory climates could also impact the carrying value of assets, including goodwill.

Estimated recoverable reserves and resources

Mineral reserve and resource estimates are based on various assumptions relating to operating matters, including, with respect to production costs, mining and processing recoveries, cut-off grades, as well as assumptions relating to long-term commodity prices and, in some cases, exchange rates, inflation rates and capital costs. Cost estimates are based on feasibility study estimates or operating history. Estimates are prepared by appropriately qualified persons, but will be impacted by forecasted commodity prices, inflation rates, exchange rates, capital and production costs and recoveries amongst other factors. Estimated recoverable reserves and resources are used to determine the depreciation of property, plant and equipment at operating mine sites, in accounting for deferred stripping costs, in performing impairment testing and for forecasting the timing of the payment of decommissioning and restoration costs. Therefore, changes in the assumptions used could impact the carrying value of assets, depreciation and impairment charges recorded in the income statement and the carrying value of the decommissioning and restoration provision.

Current and deferred taxes

The Company calculates current and deferred tax provisions for each of the jurisdictions in which it operates. Actual amounts of income tax expense are not final until tax returns are filed and accepted by the relevant authorities. This occurs subsequent to the issuance of financial statements. Therefore, profit in subsequent periods will be affected by the amount that estimates differ from the final tax returns.

Estimates of recoverability are required in assessing whether deferred tax assets and certain deferred tax liabilities are recognized on the balance sheet. The Company also evaluates the recoverability of deferred tax assets based on an assessment of the ability to use the underlying future tax deductions before they expire against future taxable income. Deferred tax liabilities arising from temporary differences on investments in subsidiaries, joint ventures and associates are recognized unless the reversal of the temporary differences is not expected to occur in the foreseeable future and can be controlled.

Assumptions about the generation of future taxable profits and repatriation of retained earnings depend on management’s estimates of future production and sales volumes, commodity prices, reserves, operating costs, decommissioning and restoration costs, capital expenditures, dividends and other capital management transactions.

Judgement is also required in the application of income tax legislation. These estimates and judgments are subject to risk and uncertainty and could result in an adjustment to current and deferred tax provisions and a corresponding credit or debit to profit.

Impairment of non-current assets and goodwill

Non-current assets are tested for impairment when events or changes in circumstances suggest that the carrying amount may not be fully recoverable. We conduct an annual test for impairment of goodwill in the fourth quarter of each fiscal year and at any other time of the year if an indicator of impairment is identified.

Calculating the estimated fair values of CGUs for non-current asset impairment tests and CGUs or groups of CGUs for goodwill impairment tests requires management to make estimates and assumptions with respect to future production levels, operating and capital costs in our life-of-mine (“LOM”) plans, long-term metal prices, foreign exchange rates and discount rates. Changes in any of the assumptions or estimates used in determining the fair values could impact the impairment analysis.

Management is also required to make judgments with respect to the level at which goodwill is tested for impairment. Judgments include an assessment of whether CGUs should be grouped together for goodwill testing purposes at a level not larger than an operating segment or tested at the individual CGU level.