Stocks of produced fixed assets and inventories

10.56 Constant-price data are needed both for stocks of produced fixed assets and for inventories. For the former, such data as are necessary for the calculation of capital output ratios are available if use is made of the perpetual inventory method. In other cases information on the values of stocks of assets may be collected from producers and deflation made by the price indices used for fixed capital formation, taking into account the age structure of stocks.

Changes in inventories are measured by the value of entries into inventories less the value of withdrawals from inventories, and the value of any recurrent losses of goods held in inventories during a given period. Constant-price estimates can be derived by the deflation of these components. When changes in the volume and the prices of inventories are fairly regular, estimates of changes in inventories can also be obtained by multiplying the volume change of inventories by average prices for the current year or the base year. As a second alternative and as a cross-check, estimates of changes in inventories can also be obtained as the difference between stocks of inventories held at the end and the beginning of the period, respectively. For this purpose the value of inventories minus revaluation according to the accounts of producers has to be revalued and expressed at the average prices, either relating to the current year or to the base-year. If they refer to the current year, the value measures the volume changes in inventories at current prices. If the average prices refer to a base-year, the value corresponds to volume changes in inventories at base-year prices.