A common issue in business and in business studies is whether a firm should change the prices at which products are offered. The calculations begin with estimates of the reaction of customers to the new prices. This reaction is represented as Price Elasticity of Demand (PED), the ratio of the proportionate changes in volume and price.
Students are always told - and some students even remember that Elastic Demand (PED >1) means more revenue from a lower price and less from a higher one; and Inelastic Demand (PED
But who wants the same revenue with lower profits? Any change in price will have a much bigger impact, proportionately, on the contribution per item for the firm than on the asking price to the customer. It follows that an increase in price may succeed in raising profits, even though revenue falls; and that a lower price may reduce profits even though revenue increases. So the critical question is not whether the PED is greater or less than one, but whether it is sufficiently high (for a lower price) or sufficiently low (for a price increase) to improve profits.
The critical level of PED can be found by an application of breakeven analysis. We can take the current level of contribution to overheads and profit; and ask what the volume (units sold) must be to give the same level of contribution at the alternative price.
Having found this critical volume, we can then compute what the PED would be to give us this volume at the new price, compared with the existing price and quantity. This then will be the Critical Price Elasticity of Demand (CPED). If we are raising prices, any PED less than CPED will increase profits; if we are lowering