Cumulative effect of changes in accounting policies (principles) is the difference between the book value of the affected assets (or liabilities) under the old policy (principle) and what the book value would have been if the new principle had been applied in the prior periods. For example, valuation of inventories using LIFO instead of weighted average method. The changes should be applied retrospectively and shown as adjustments to the "beginning" balance of affected components in Equity. All comparative financial statements should be restated. (IAS 8)