Elasticity

Summary and Exam Tips for Elasticity

Elasticity is a subtopic of The Market System, which falls under the subject Economics in the Edexcel IGCSE curriculum. Elasticity measures how much the quantity demanded or supplied of a product changes in response to changes in price or income.

• Price Elasticity of Demand (PED): This measures the responsiveness of quantity demanded to a change in price. The formula is $\text{PED} = \frac{\%\text{ change in quantity demanded}}{\%\text{ change in price}}$. Key factors affecting PED include substitutes, necessity, income proportion, and time. PED values indicate whether demand is elastic, inelastic, or unitary.

• Price Elasticity of Supply (PES): This measures the responsiveness of quantity supplied to a change in price. The formula is $\text{PES} = \frac{\%\text{ change in quantity supplied}}{\%\text{ change in price}}$. Factors affecting PES include production factors, stock availability, spare capacity, and time.

• Income Elasticity of Demand (YED): This measures how quantity demanded changes with income changes. The formula is $\text{YED} = \frac{\%\text{ change in quantity demanded}}{\%\text{ change in income}}$. YED helps classify goods as normal, inferior, or luxury.

Understanding these elasticities helps businesses and governments make informed decisions about pricing, production, and taxation.

Exam Tips

• Understand Key Formulas: Memorize the formulas for PED, PES, and YED. Practice calculating these using percentage changes.

• Interpret Elasticity Values: Be able to interpret numerical values of elasticity to determine if demand or supply is elastic, inelastic, or unitary.

• Use Diagrams: Practice drawing and interpreting diagrams that show price elastic and inelastic demand and supply.

• Factors Affecting Elasticity: Familiarize yourself with the factors that influence PED and PES, such as substitutes, necessity, and time.

• Real-World Applications: Consider how elasticity affects business decisions and government policies, such as pricing strategies and tax impositions.