ELASTICITY A concept used by economists to measure the responsiveness of people to changes in economic variables.
ELASTICITY If people are very responsive to changes in economic variables, the measure is said to be elastic or highly elastic. If people are not very responsive to changes in economic variables, the measure is said to be inelastic.
PRICE ELASTICITY OF DEMAND • How much more of a product will a consumer buy when the product price decreases. • How much less of a product will a consumer buy when the product price increases. • What is the responsiveness of consumers to changes in price.
PRICE ELASTICITY OF DEMAND percentage change in quantity demanded Ed= ----------------------percentage change in price • Percentage change in price equals the absolute change in price divided by the initial price; • Percentage change in quantity equals the absolute change in quantity divided by the initial quantity.
PRICE ELASTICITY OF DEMAND • If the price of milk increases from $2. 00/quart to $2. 20/quart, and • the resulting quantity demanded changes from 100 million gallons of milk to 85 gallons of milk, • what is the elasticity of demand for milk ?
PRICE ELASTICITY OF DEMAND % change Quantity Ed = -------------------% change Price (New Quantity - Original Quantity) / (Original Quantity) Ed = --------------------------------(New Price - Original Price) / (Original Price)
PRICE ELASTICITY OF DEMAND PRICE OF MILK $$ Market Demand Curve $2. 20 $2. 00 85 • 100 Millions of Gallons of Milk per Year (85 -100) / 100 -15 / 100 Ed = ---------------$2. 20 -$2. 00) / $2. 00 $0. 20 / $2. 00 • Ed = 15% / 10% = 1. 50 Demand is elastic.
PRICE ELASTICITY OF DEMAND Midpoint (More Precise) Approach % change Quantity Ed = --------------% change Price (New Quantity - Original Quantity) / (Average Quantity) Ed = --------------------------------(New Price - Original Price) / (Average Price)
PRICE ELASTICITY OF DEMAND Midpoint (More Precise) Approach PRICE OF MILK $$ Market Demand Curve $2. 20 $2. 00 85 • 100 Millions of Gallons of Milk per Year [ (85 - 100) ÷ (85 +100) ] / 2 Ed = ------------------[ ($2. 20 - $2. 00) ÷ ($2. 20 + $2. 00) ] / 2 • -15 / 92. 5 16. 22% Ed = -------------- = 1. 70 Demand is elastic. $0. 20 / $2. 9. 52%
THREE ELASTICITY GROUPS OF CONSUMER DEMAND GROUP QUANTITY TO PRICE RELATIONSHIP VALUE ELASTIC Percentage change in quantity >1 greater than percentage change in price. INELASTIC Petrcentage change in quantity less than percentage change in price. <1 UNIT ELASTIC =1 Percentage change in quantity equal to percentage change in price.
PRICE ELASTICITY AND SUBSTITUTES • NO GOOD SUBSTITUTES -Consumers are not very responsive to changes in price; Example: insulin for diabetics; Price elasticity of demand is inelastic. • MANY SUBSTITUTES -Consumers will readily switch to alternative product for small price changes; Example: cornflakes; Price elasticity of demand is elastic.
Estimated Price Elasticities of Demand for Selected Products PRODUCT salt water coffee cigarettes shoes and footware housing automobiles foreign travel restaurant meals air travel motion pictures ELASTICITY 0. 1 0. 2 0. 3 0. 7 1. 0 1. 2 1. 8 2. 3 2. 4 3. 7
Other Determinants of Demand Elasticity • TIME Greater time permits finding more substitutes; consequently, elasticity of demand increases with time: Greater time -- greater elasticity. • PERCENTAGE OF BUDGET The smaller the price of a product with respect to the size of the household budget, the more inelastic will be the product demand. • NECESSITIES VERSUS LUXURIES The greater the need for a product, the more inelastic will be the product demand.
Elasticity Along a Linear Demand Curve PRICE $$ Elasticity = 4 = (20% / 5%) 80 76 Elasticity = 1. 0 = (8% / 8%) Elasticity = 0. 25 = (5% / 20%) 50 46 20 16 10 12 25 27 40 42 QUANTITY CONSUMED PER DAY
Elasticity Along a Linear Demand Curve PRICE $$ Elasticity = 4 : ELASTIC 80 76 Elasticity = 1. 0 : UNIT ELASTIC Elasticity = 0. 25 : INELASTIC 50 46 20 16 10 12 25 27 40 42 QUANTITY CONSUMED PER DAY
Using Elasticity of Demand to Calculate Change in Quantity Demanded GIVEN: • Elasticity of Demand; • Percentage change in Price; • Ed = % change Quantity ÷ % change Price; Percentage change in quantity may be calculated from the two known values: • % change Quantity = Ed x % change Price
Using Elasticity of Demand to Predict changes in Total Revenue DEMAND Elastic PRICE TOTAL REVENUE Increase Declines Decrease Increases (A negative relationship exists between price and total revenue for an elastic demand. ) Inelastic Increase Decrease Increases Declines (A positive relationship exists between price and total revenue for an inelastic demand. )
PRICE ELASTICITY OF SUPPLY • How much more of a product will a producer make when the product price increases. • How much less of a product will a producer make when the product price drops. • What is the responsiveness of producers to changes in price.
PRICE ELASTICITY OF SUPPLY percentage change in quantity supplied Ed= --------------------percentage change in price • Percentage change in price equals the absolute change in price divided by the initial price; • Percentage change in quantity equals the absolute change in quantity divided by the initial quantity.
PRICE ELASTICITY OF SUPPLY • If the price of milk increases from $2. 00/quart to $2. 20/quart, and • the resulting quantity supplied changes from 100 million gallons of milk to 120 gallons of milk, • what is the elasticity of supply for milk ?
Elasticity of Supply % change Quantity Es = ---------------% change Price ; (New Quantity - Original Quantity) / (Average Quantity) - Es = ----------------------(New Price - Original Price) / (Average Price)
Elasticity of Supply PRICE OF MILK $$ $2. 20 Market Supply Curve $2. 00 120 Millions of Gallons of Milk per Year (20 /110) = ------------- = 20% /10% = 2. 0 ( $0. 20 / $2. 10) Supply is elastic; Es
PRICE ELASTICITY OF SUPPLY • Increases with time; • Limitations of production facilities in the short run prevent firms from responding with as much output increase as price increases; • As firms can increase production facilities, in the longer run, the larger will be the increase in quantity supplied.
Predicting Price Changes Using Elasticities An increase in demand (i. e. , rightward shift): • results in shortage at original price (demand exceeds supply); • establishes market equilibrium at higher price, and quantity between original equilibrium quantity and quantity consumers now willing to buy at original price; • encourages producers to supply more and consumers to buy less.
shortage PRICE OF MILK $$ Supply S 1 $2. 00 Demand D 2 Demand D 1 100 150 Millions of Gallons of Milk per Year
Predicting Price Changes Using Elasticities With an increase in demand, the resulting equilibrium price increase will be: • small if consumers and producers are very responsive to price changes (elastic demand elastic supply) ; • larger if either is not very responsive (i. e. , inelastic);
original equilibrium PRICE OF MILK $$ new equilibrium Supply S 1 $2. 05 $2. 00 Demand D 2 Demand D 1 100 130 Millions of Gallons of Milk per Year
Predicting Price Changes Using Elasticities With an increase in demand, the resulting percentage change in price can be found by: • Percentage change in price = Percentage change in demand ---------------------(Es + Ed)
Predicting Price Changes Using Elasticities With an increase in supply, the resulting percentage change in price can be found by: • Percentage change in price = Percentage change in supply ---------------------(Es + Ed)
Predicting Price Changes Using Elasticities An increase in supply (i. e. , rightward shift): • results in excess at original price (supply exceeds demand); • establishes market equilibrium at lower price, and quantity between original equilibrium quantity and quantity producers now willing to supply at original price; • encourages producers to supply less and consumers to buy more.
PRICE OF MILK $$ Supply S 1 $2. 00 Supply S 2 Demand D 1 100 Millions of Gallons of Milk per Year
Predicting Price Changes Using Elasticities With an increase in supply, the resulting equilibrium price decrease will be: • small if consumers and producers are responsive to price changes (elastic demand elastic supply) ; • larger if either is not very responsive (i. e. , inelastic);
original equilibrium PRICE OF MILK $$ new equilibrium Supply S 1 $2. 00 $1. 80 Supply S 2 Demand D 1 100 110 Millions of Gallons of Milk per Year
Скачать презентацию ELASTICITY A concept used by economists to measure
b17364ab5765a38539b1b88809fb7285.ppt