Study Notes
Cross Elasticity of Demand (XED) measures how the quantity demanded of one good responds to a change in the price of another good. It helps understand the relationship between two goods.
- Cross Elasticity of Demand (XED) — the responsiveness of quantity demanded for one good to a change in the price of another good. Example: If the price of Pepsi increases, the demand for Coca-Cola may increase.
- Substitutes — goods with a positive XED, meaning the demand for one increases when the price of the other increases. Example: Pepsi and Coca-Cola are substitutes; if Pepsi's price rises, Coca-Cola's demand increases.
- Complements — goods with a negative XED, meaning the demand for one decreases when the price of the other increases. Example: Coffee pods and coffee machines are complements; if coffee pods' price rises, coffee machines' demand decreases.
- Strong Substitutes — goods with a high positive XED, indicating a strong response in demand to price changes of substitutes. Example: Butter and margarine.
- Weak Substitutes — goods with a low positive XED, indicating a weak response in demand to price changes of substitutes. Example: Bicycles and automobiles.
- Strong Complements — goods with a low negative XED, indicating a weak response in demand to price changes of complements. Example: Software and computers.
- Weak Complements — goods with a high negative XED, indicating a strong response in demand to price changes of complements. Example: Tea and milk.
Exam Tips
Key Definitions to Remember
- Cross Elasticity of Demand (XED)
- Substitutes
- Complements
- Strong Substitutes
- Weak Substitutes
- Strong Complements
- Weak Complements
Common Confusions
- Confusing substitutes with complements
- Misunderstanding the direction of demand change for substitutes and complements
Typical Exam Questions
- What is Cross Elasticity of Demand? It measures the responsiveness of demand for one good to a change in the price of another good.
- How does the price change of a substitute affect demand? An increase in the price of a substitute increases the demand for the other good.
- How does the price change of a complement affect demand? An increase in the price of a complement decreases the demand for the other good.
What Examiners Usually Test
- Understanding of positive and negative XED values
- Ability to identify and explain examples of substitutes and complements
- Calculation and interpretation of XED values