Price Elasticity of Demand = Percentage change in quantity demanded / Percentage change in price
- Ignore the sign
- If the number is less than one, the good is inelastic
- If the number is more than one, the good is elastic
- If the number is equal to one, the good is unit elastic
Price Elasticity of Supply = Percentage change in quantity supplied / Percentage change in price
Income Elasticity of Supply = Percentage change in quantity demanded / Percentage change in income
- If the sign is +, it is a normal good
- If the sign is -, it is a inferior good
- If the sign is +, it is a substitute
- If the sign is -, it is a complement
