Functions of the price mechanism

The three functions

• Rationing: when a good becomes scarcer, its price rises, so only those most willing and able to pay buy it. Demand contracts until it matches the limited supply. Price allocates scarce goods among competing buyers.
• Incentive: a higher price raises potential profit, which encourages existing firms to produce more and new firms to enter. A lower price gives an incentive to reduce output. For consumers, a high price is an incentive to economise or find substitutes.
• Signalling: price changes give information to buyers and sellers. A rising price signals that consumers want more of a good, telling producers to move resources towards it; a falling price signals that resources should move elsewhere.

Together these allocate resources without anyone directing them: Adam Smith's 'invisible hand'.

A worked chain

Suppose demand for electric cars increases. Demand shifts right; at the old price there is excess demand. The price rises (signal) and higher profits give an incentive for manufacturers to switch resources into electric cars, so supply extends and in the long run new capacity is built. Meanwhile the higher price rations the limited supply among buyers. Resources move from petrol cars to electric cars.

Local, national and global markets

• Local: prices of houses or restaurant meals in one town respond to local demand and supply.
• National: wages for a profession across a country, or train fares.
• Global: commodities such as oil, wheat, copper and coffee are traded worldwide, so a drought in one major producing country raises prices for buyers everywhere, signalling to farmers elsewhere to grow more.

Evaluate: the price mechanism does not always work well. Information is imperfect, consumers may not act rationally, and prices ignore external costs and benefits (market failure). Rationing by price can be seen as unfair, because goods go to those with the most money rather than the greatest need.

Worked example

A frost destroys much of the orange crop in a major growing region. Use the functions of the price mechanism to explain what happens.

1. Supply shifts left, so at the old price there is excess demand and the price rises.
2. Rationing: the higher price limits purchases to those most willing and able to pay.
3. Signalling: the higher price shows producers elsewhere that oranges are scarce.
4. Incentive: higher profits encourage other growers to supply more, and consumers to switch to other fruit.

Answer: Price rises, rationing the smaller crop, signalling scarcity and giving an incentive to supply more.

Check yourself

1. Tickets for a popular concert are sold at a high market price, so only those most willing and able to pay attend. Which function is this?
   • Signalling
   • Incentive
   • Rationing
   • Specialisation
   Show answer

   Rationing. Price allocates a fixed number of tickets among buyers.

2. A rise in the price of cocoa leads farmers to plant more cocoa trees. Which function of the price mechanism does this show most directly?
   • Incentive
   • Rationing
   • Unit of account
   • Inertia
   Show answer

   Incentive. Higher potential profit encourages more production.

3. A sustained fall in the price of a product mainly signals to producers that
   • they should increase output
   • demand has become perfectly inelastic
   • resources should be moved to other uses
   • the government will provide a subsidy
   Show answer

   resources should be moved to other uses. Lower price means lower profit, so resources move elsewhere.

4. Which is the best example of the price mechanism working in a global market?
   • A local bakery raising the price of bread
   • The world price of oil rising after supply cuts by major producers
   • A town council setting parking charges
   • A school fixing the price of lunches
   Show answer

   The world price of oil rising after supply cuts by major producers. Oil is traded worldwide, so supply changes anywhere affect prices everywhere.

5. Which is a limitation of the price mechanism?
   • It sends signals to producers
   • It rations scarce goods
   • It encourages firms to respond to consumers
   • It ignores external costs such as pollution
   Show answer

   It ignores external costs such as pollution. Market prices reflect private costs and benefits only.

6. Explain the signalling function of the price mechanism.
   Show answer

   Changes in price give information to producers and consumers. A rising price signals that a good is scarce or in greater demand, telling producers to move more resources into producing it; a falling price signals that resources should move elsewhere.. Information carried by price changes leads to reallocation.

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Sources

• Pearson Edexcel International Advanced Subsidiary/Advanced Level in Economics specification (2018)

Last updated 8 November 2026. Spotted a mistake? Tell us.