2.6

Price elasticity of demand

Cambridge IGCSE Economics (0455)  · Unit 2: The allocation of resources  · 10 flashcards

Price elasticity of demand is topic 2.6 in the Cambridge IGCSE Economics (0455) syllabus , positioned in Unit 2 — The allocation of resources , alongside Microeconomics and macroeconomics, The role of markets and Demand.  In one line: PED measures the responsiveness of quantity demanded to a change in price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price. A higher PED value indicates greater responsiveness.

This topic is examined in Paper 1 (multiple-choice) and Paper 2 (structured questions, including data-response items).

The deck below contains 10 flashcards — 1 definition, 5 key concepts and 3 application cards — covering the precise wording mark schemes reward.  Use the definition card to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

Price Elasticity of Demand (PED)

PED measures the responsiveness of quantity demanded to a change in price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price. A higher PED value indicates greater responsiveness.

Questions this Price elasticity of demand deck will help you answer

Definition Flip

Define Price Elasticity of Demand (PED).

Answer Flip

PED measures the responsiveness of quantity demanded to a change in price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price. A higher PED value indicates greater responsiveness.

Key Concept Flip

Explain what it means for a good to have elastic demand.

Answer Flip

Elastic demand means that the quantity demanded is very sensitive to a change in price. A small price change leads to a relatively larger change in quantity demanded. Elastic goods typically have PED > 1.

Key Concept Flip

Explain what it means for a good to have inelastic demand.

Answer Flip

Inelastic demand means that the quantity demanded is not very sensitive to a change in price. A change in price leads to a relatively smaller change in quantity demanded. Inelastic goods typically have PED < 1.

Key Concept Flip

What does it mean for a good to have unit elastic demand?

Answer Flip

Unit elastic demand means that the percentage change in quantity demanded is equal to the percentage change in price. The PED value is equal to 1.

Example: a 10% price increase leads to a 10% decrease in quantity demanded.
Key Concept Flip

Write the formula for calculating PED.

Answer Flip

PED = (% Change in Quantity Demanded) / (% Change in Price). Remember to use percentage changes for both numerator and denominator to get an accurate elasticity value.

Key Concept Flip

How does PED affect a firm's decision to change the price of a good?

Answer Flip

If demand is elastic, a firm may choose to lower prices to increase total revenue. If demand is inelastic, a firm may choose to increase prices to increase total revenue. This is because the change in quantity will be proportionately less than the change in price.

Key Concept Flip

What is the relationship between PED and total revenue?

Answer Flip

If demand is elastic, a price decrease will increase total revenue, and a price increase will decrease total revenue. The opposite is true for inelastic demand: a price increase will increase total revenue.

Key Concept Flip

Explain how the availability of substitutes affects PED.

Answer Flip

Goods with many close substitutes tend to have more elastic demand. Consumers can easily switch to a different product if the price increases.

Example: Different brands of bottled water.
Key Concept Flip

Explain how whether a good is a necessity or a luxury affects PED.

Answer Flip

Necessities tend to have inelastic demand because people will continue to buy them even if the price increases. Luxuries tend to have elastic demand because people can easily postpone or forgo the purchase if the price increases.

Example: Bread (necessity) vs. a designer handbag (luxury).
Key Concept Flip

Outline two factors that determine PED.

Answer Flip

The number and closeness of substitutes, and whether the good is a necessity or a luxury. A product with lots of substitutes that is considered a luxury will have a high PED. A product with few substitutes that is considered a necessity will have a low PED.

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2.5 Price determination 2.7 Price elasticity of supply

Key Questions: Price elasticity of demand

Define Price Elasticity of Demand (PED).

PED measures the responsiveness of quantity demanded to a change in price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price. A higher PED value indicates greater responsiveness.

More topics in Unit 2 — The allocation of resources

Price elasticity of demand sits alongside these Economics decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0455 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

PED price elasticity elastic inelastic unit elastic percentage change total revenue necessity luxury substitutes

Key terms covered in this Price elasticity of demand deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

Price Elasticity of Demand (PED)

How to study this Price elasticity of demand deck

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