Accountants prepare income statements typically in terms of historical costs, in terms of the purchase price, rather than in terms of the current price. The reasons given for this practice are:
1. Historical costs produce more accurate measurement of the income.
2. Historical costs are less debatable and more objective than the calculated present replacement value, and
3. Accountants' job is to record historical costs whether or not they may have relevance for further decision making. The accountants approach ignores certain important changes in earning and losses of the firms, (1) the value of assets presented in the books of accounts is understand in times of inflation and overstated at the time of the deflection, depreciation is understand during deflection. Historical cost recording does not reflect such changes in values of assets and profits. This problem assumes a critical importance in case of the inventories and stock. The problem is how to evaluate the inventory and the goods in the pipeline. There are three common techniques of inventory valuation: (1) first in first out (FIFO), (2) last in first out (LIFO), and (3) weighted average cost (WAC). Under FIFO method, material is taken out of the stock for further processing in the order in which they are acquired. The stocks, therefore appear in the firms balance sheet at their actual cost price. This method is suitable when price has a secular trend. However, this system exaggerates profits at the time of rising prices. The LIFO method assumes that stocks purchased most recently become the costs of the raw material in the current production. If inventory levels are stable the cost of the raw materials used at any point in the calculation of profits is always close to market or replacement value. But when inventory levels fluctuate this method loses its advantages. The WAC method takes the weighted average of the costs of materials purchased at different prices and different points of time to evaluate the inventory. All these methods have their own weaknesses and do not reflect the true profit of business. So the problem of evaluating inventories so as to yield a true profit figure remains there.