2.3

Price Elasticity of Demand

AP Microeconomics

What is price elasticity of demand?

The midpoint method

Worked example

Classifying elasticity

123456789101112123456789101112QuantityPrice ($)Perfectly InelasticPerfectly ElasticUnit Elastic (linear reference)

Perfectly inelastic (vertical), perfectly elastic (horizontal), and unit elastic reference

Elasticity along a linear demand curve

123456789101112123456789101112QuantityPrice ($)Elastic (|Ed|>1)Unit Elastic (|Ed|=1)Inelastic (|Ed|<1)Demand

Elasticity varies along a linear demand curve

Determinants of elasticity

Examples

Elasticity and total revenue

Why?

Memory trick

Graphing total revenue

12345678910111212345678910111213141516171819202122232425262728QuantityTotal Revenue ($)TR max (unit elastic)Total Revenue

TR is maximized where demand is unit elastic

AP exam tips for 2.3

Common mistakes

Key equations

Vocabulary