To illustrate: assume sales revenue is £1,000,000 and accounting cost is £900,000; on conventional criteria the firm thus makes an accounting profit of £100,000. However, when allowance is made for the opportunity cost of the firm's assets if liquidated and redeployed in an alternative use the picture changes. If the firm's assets could have earned, say, £200,000 in some alternative activity (e.g. even putting the money on interest-bearing deposit with a bank) then the positive accounting profit is turned into an economic loss of £100,000. Thus, shareholders' wealth has been ‘destroyed’ rather than ‘created’.
However, whilst producing accurate accounting cost and profit data can be difficult, obtaining reliable economic cost and profit data can be even more problematic. For example, a high proportion of the investment in the firm's current activity may represent a ‘sunk’ cost with little prospect of recovery if liquidated, while there is a difficulty in identifying which are likely to be viable alternative activities where the firm's new investment might yield higher profit returns than currently being achieved.