This document discusses price elasticity of demand and its importance. It defines three types of price elasticity: inelastic (elasticity less than 1), unit elastic (elasticity equals 1), and elastic (elasticity greater than 1). It also discusses perfect inelasticity (elasticity equals 0) and perfect elasticity (elasticity equals infinity). The document explains how changes in price affect quantity demanded for each type and presents examples using demand curves. Additional topics covered include determinants of price elasticity, its relationship to total revenue, and income elasticity for normal versus inferior goods.

1. ELASTIC VS. INELASTIC

2. HOW MUCH MORE OR LESS?
DOES IT MATTER? to whom?
Think About It...
THE LAW OF DEMAND SAYS...
PRICE ELASTICITY OF DEMAND
Consumers will buy more when
prices go down and less when
prices go up
Price Elasticity Provides an Answer

3. RANGES OF ELASTICITY
Inelastic Demand
Percentage change in price is greater than percentage change in
quantity demand.
Price elasticity of demand is less than one.
Elastic Demand
Percentage change in quantity demand is greater than percentage
change in price.
Price elasticity of demand is greater than one.

4. PERFECTLY INELASTIC DEMAND
- ELASTICITY EQUALS 0
Quantity
Price
4
$5
Demand
100
2. ...leaves the quantity demanded unchanged.
1. An
increase
in price...

5. INELASTIC DEMAND
- ELASTICITY IS LESS THAN 1
Quantity
Price
4
$5
1. A 25%
increase
in price...
Demand
100
90
2. ...leads to a 10% decrease in quantity.

6. UNIT ELASTIC DEMAND
- ELASTICITY EQUALS 1
Quantity
Price
4
$5
1. A 25%
increase
in price...
Demand
100
75
2. ...leads to a 25% decrease in quantity.

7. ELASTIC DEMAND
- ELASTICITY IS GREATER THAN 1
Quantity
Price
4
$5
1. A 25%
increase
in price...
Demand
100
50
2. ...leads to a 50% decrease in quantity.

8. PERFECTLY ELASTIC DEMAND
- ELASTICITY EQUALS INFINITY
Quantity
Price
Demand
$4
1. At any price
above $4, quantity
demanded is zero.
2. At exactly $4,
consumers will
buy any quantity.
3. At a price below $4,
quantity demanded is infinite.

9. DETERMINANTS OF PRICE
ELASTICITY OF DEMAND
•Substitutability: Generally, the more substitute goods available, the
greater the price elasticity of demand.
•Proportion of Income: Other things equal, the higher the price of a
good relative to consumers’ incomes, the greater the price elasticity of demand.
•Luxuries versus Necessities: In general, the more a good is
considered to be a “luxury”, the greater is the price elasticity of demand.
•Time: Generally, product demand is more elastic the longer the time period
under consideration. Consumers often need time to adjust to changes in prices.

10. ELASTICITY AND TOTAL REVENUE
Total revenue is the amount paid by buyers and
received by sellers of a good.
Computed as the price of the good times the
quantity sold.
TR = P x Q

13. INCOME ELASTICITY
- TYPES OF GOODS -
Normal Goods
Income Elasticity is positive.
Inferior Goods
Income Elasticity is negative.
Higher income raises the quantity demanded for
normal goods but lowers the quantity demanded
for inferior goods.

14. ELASTIC, INELASTIC, OR UNIT ELASTIC

15. ELASTIC, INELASTIC, OR UNIT ELASTIC

19. ELASTIC, INELASTIC, OR UNIT ELASTIC