Tag: inelastic

The law of demand tells us that when the price of a good falls, quantity demanded will rise. But, firms want to know much more than this. They need to know by how much quantity demanded will rise – we refer to this as the price elasticity of demand (PED) and we can categorise it as relatively inelastic or elastic, depending on by how much demand changes relative to the change in price. The price elasticity of demand is crucial for a firm to know, as it gives them vital information about the best price to charge and getting the price right is probably the most important element in a successful business. As Warren Buffett said in a meeting with the staff from the Federal Crisis Inquiry Commission:

‘Basically, the single most important decision in evaluating a business is pricing power. You’ve the power to raise prices without losing business to a competitor, and you’ve got a very good business. And if you have to have a prayer session before raising the price by a tenth of a cent, then you got a terrible business.’

The grammar may not be entirely correct, but hopefully you get the gist! Should a firm increase price or reduce it? Whatever action it takes, there will be an effect on demand, total revenue and profit. The key question is: what will be the effect? The answer depends on the PED.

If a firm is selling a product for which there are no close substitutes, we would expect demand to be relatively inelastic. This means that the firm can increase the price it charges without seeing any large fall in quantity. On the other hand, if a firm faces a lot of competition and hence there are many substitutes for a product, then demand becomes much more elastic – any increase in a firm’s price will lead to a proportionately larger decrease in the quantity demanded, as customers will simply switch to a cheaper alternative. The article below looks at the concept of price elasticity of demand and how it is used in practice by competing firms.

The importance of pricing power: PEP, CPB Guru Focus (16/10/11)
Pricing strong for Philip Morris in Q3, but volumes also encouraging; dividend yield attractive MorningStar (7/11/11)


  1. How do we define price elasticity of demand and what formula can we use to calculate it?
  2. If a firm faces an PED of –5, is its demand relatively inelastic or elastic and what does it mean about the responsiveness of customer demand to a change in price?
  3. If a firm faces demand that is (a) relatively inelastic (b) relatively elastic, (c) perfectly elastic (d) perfectly inelastic, what should it do to its price? Explain your answers.
  4. In the article, ‘The importance of pricing power’, is demand for the ‘Daily Racing Forum’ relatively inelastic or elastic? Explain your answer and what it means in terms of the company’s ability to change price.
  5. Is demand for cigarettes likely to be inelastic or elastic? Explain your answer. What does this suggest about a firm’s ability to pass on taxation and excise duties to its customers in the form of higher prices?
  6. Based on the data given in ‘The importance of pricing power’ about the change in demand for Campbell’s Soup and PepsiCo, what conclusions can we reach about PED? How could these firms use this information to set prices and maximise revenue and profit?
  7. Following a change in supply (due to a factor other than price), when will the impact on equilibrium price be larger than the impact on equilibrium quantity?