The indirect energy requirement of a product can be significantly affected by the energy requirement of the retail trade. In previous studies this was generally assigned on a financial basis (twice the price results in twice the energy requirement); the financial accounting method. But the energy requirement of the retail trade can also be assigned on a physical basis (twice the amount product (e.g. kg, m3) results in twice the energy requirement); the physical accounting method. To get an idea of the error made with these methods a detailed energy analysis has been made for two retail branches: clothes shops and shoe shops.
Both methods may give serious errors, 5 to 15 % of the total indirect energy requirement for clothes and shoes if they have a price level deviation from the average price. Unfortunately, neither the physical or the financial accounting method can be indicated as the preferred method.