1. F ERNANDO Q UIJANO, Y VONN Q UIJANO, K YLE T HIEL & A PARNA S UBRAMANIAN PREPARED BY: © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez Elasticity: A Measureof Responsiveness

2. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 2 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 price elasticity of demand (E d ) A measure of the responsiveness of the quantity demanded to changes in price; equal to the absolute value of the percentage change in quantity demanded divided by the percentage change in price.

3. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 3 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Computing Percentage Changes and Elasticities Table 4.1 COMPUTING PRICE ELASTICITY WITH INITIAL VALUES AND MIDPOINTS PriceQuantity DataInitial$20100 New2280 PriceQuantity Computation with Initial- value method Percentage change Price elasticity of demand PriceQuantity Computation with Midpoint method Percentage change Price elasticity of demand

4. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 4 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Price Elasticity and the Demand Curve Figure 4.1 shows five different demand curves, each with a different elasticity. We can divide products into five types, depending on their price elasticities of demand. FIGURE 4.1 Elasticity and Demand Curves elastic demand The price elasticity of demand is greater than one.

5. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 5 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Price Elasticity and the Demand Curve FIGURE 4.1 (contd.) Elasticity and Demand Curves inelastic demand The price elasticity of demand is less than one.

6. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 6 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Price Elasticity and the Demand Curve FIGURE 4.1 (contd.) Elasticity and Demand Curves unit elastic demand The price elasticity of demand is one.

7. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 7 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Price Elasticity and the Demand Curve FIGURE 4.1 (contd.) Elasticity and Demand Curves perfectly inelastic demand The price elasticity of demand is zero.

8. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 8 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Price Elasticity and the Demand Curve FIGURE 4.1 (contd.) Elasticity and Demand Curves perfectly elastic demand The price elasticity of demand is infinite.

9. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 9 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Elasticity and the Availability of Substitutes

10. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 10 of 37 THE PRICE ELASTICITY OF DEMAND 4.1 Other Determinants of the Price Elasticity of Demand

11. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 11 of 37 USING PRICE ELASTICITY TO PREDICT CHANGES IN QUANTITY 4.2 If we have values for two of the three variables in the elasticity formula, we can compute the value of the third. The three variables are: (1)the price elasticity of demand itself, (2)the percentage change in quantity, and (3)the percentage change in price. Specifically, we can rearrange the elasticity formula: percentage change in quantity demanded = percentage change in price × E d

12. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 12 of 37 WHY YOULL PAY MORE IN RENT THIS YEAR The current rental market is extremely hot with the average rent reaching $940 per month for the last quarter of 2005. Some areas such as New York City reported rents averaging $2,400 per month. In spite of these numbers, many analysts believe rent is still low in several regions. In some areas such as Ft. Lauderdale Florida, rent has climbed almost 12% in the recent months as occupancy rates approached 100% and is expected to go higher. Much of the reason for higher rents is supply related due to many apartment units being converted to condominiums. Other regions, particularly along the Gulf Coast, can thank Hurricane Katrina for the rental unit shortage. With apartments being difficult to find vacant, many owners are using the hot market to increase rents a little. Rising home prices and increasing rates also alter the picture and push a number of people back to the rental market. Houses are getting too expensive for some people to own. A decrease in the supply of rental units will automatically push prices higher. Owners, looking to make a profit, tend to react very quickly to high occupancy rates. However, new units will no doubt soon be constructed to lessen the shortage. Extra Application 8

13. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 13 of 37 BEER TAXES AND HIGHWAY DEATHS APPLYING THE CONCEPTS #1: How can we use the price elasticity of demand to predict the effects of taxes? The price elasticity of demand for beer among young adults is about 1.30. If a state imposes a beer tax that increases the price of beer by 10 percent, how will the price hike affect beer consumption among young adults? Using the elasticity formula, we predict that beer consumption will decrease by 13 percent: percentage change in quantity demanded = percentage change in price × E d = 10% × 1.30 = 13% The number of highway deaths among young adults is roughly proportional to their beer consumption, so the number of deaths will also decrease by 13 percent. Larger taxes would decrease beer consumption and highway deaths by larger amounts. We can use the concept of price elasticity to predict the effects of a change in the price of beer on drinking and highway deaths among young adults.

14. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 14 of 37 SUBSIDIZED MEDICAL CARE IN CÔTE DIVOIRE AND PERU APPLYING THE CONCEPTS #2: Does the responsiveness of consumers to changes in price vary by income? In Côte dIvoire in Africa, the price elasticity of demand for hospital services is 0.47 for poor households and 0.29 for wealthy households. A 10-percent increase in the price of hospital services would cause poor households to cut back their hospital care by: percentage change in quantity demanded = 10% × 0.47 = 4.7% In contrast, wealthy households would cut back by: percentage change in quantity demanded = 10% × 0.29 = 2.9% In Peru, the price elasticity is 0.67 for poor households but only 0.03 for wealthy households. How would the higher price affect its poor and wealthy households? The poor are much more sensitive to price, so when prices increase, they experience much larger reductions in medical care. Many developing nations subsidize medical care, charging consumers a small fraction of the cost of providing the services. If a nation were to cut its subsidies and thus increase the price of medical care for consumers, how would the higher price affect its poor and wealthy households?

15. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 15 of 37 PRICE ELASTICITY AND TOTAL REVENUE 4.3 total revenue The money a firm generates from selling its product. total revenue = price per unit × quantity sold

16. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 16 of 37 HOW TO CUT TEEN SMOKING BY 60 PERCENT APPLYING THE CONCEPTS #3: How can we use the price elasticity of demand to predict the effects of public policies? The demand for cigarettes by teenagers is elastic, with an elasticity of 1.3. Therefore, a 25-percent price hike will reduce teen smoking by only 32.5 percent, far short of the target reduction: percentage change in quantity demanded = 25% × 1.30 = 32.5% About half of the decrease in consumption occurs because fewer teenagers will become smokers, and the other half occurs because each teenage smoker will smoke fewer cigarettes. To meet the target reduction of teenage smoking, the price of cigarette prices must increase by about 46 percent: percentage change in quantity demanded = 46% × 1.3 = 60% Under the 1997 federal tobacco settlement, if smoking by teenagers does not decline by 60 percent by the year 2007, cigarette makers will be fined $2 billion. The settlement increased cigarette prices by about 62 cents per pack, a percentage increase of about 25 percent. Will the price hike be large enough to meet the target reduction of 60 percent?

17. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 17 of 37 PRICE ELASTICITY AND TOTAL REVENUE 4.3 Elastic Versus Inelastic Demand

18. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 18 of 37 PRICE ELASTICITY AND TOTAL REVENUE 4.3 Elastic Versus Inelastic Demand

19. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 19 of 37 A BUMPER CROP IS BAD NEWS FOR FARMERS APPLYING THE CONCEPTS #4: If demand is inelastic, how does an increase in supply affect total expenditures? The good news is that farmers will sell more bushels of soybeans. The bad news is that the increase in supply will decrease the equilibrium price of soybeans, so they will get less money per bushel. Which will be larger, the increase in quantity or the decrease in price? The demand for soybeans and many other agricultural products is inelastic. To increase the quantity demanded by 30 percent to meet the higher supply, the price must decrease by more than 30 percent. Consumers need a large price reduction to buy more of the product. Suppose that favorable weather generates a bumper crop for soybeans that is 30 percent larger than last years harvest. If the price elasticity of demand is 0.75, the price must decrease by 40 percent to increase the quantity demanded by 30 percent. To show this, we can rearrange the elasticity formula:

20. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 20 of 37 ELASTICITY AND TOTAL REVENUE FOR A LINEAR DEMAND CURVE 4.4 Price Elasticity Along a Linear Demand Curve FIGURE 4.2 Elasticity and Total Revenue Along a Linear Demand Curve

21. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 21 of 37 ELASTICITY AND TOTAL REVENUE FOR A LINEAR DEMAND CURVE 4.4 Price Elasticity Along a Linear Demand Curve

22. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 22 of 37 OTHER ELASTICITIES OF DEMAND 4.5 Income Elasticity of Demand income elasticity of demand A measure of the responsiveness of demand to changes in consumer income; equal to the percentage change in the quantity demanded divided by the percentage change in income.

23. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 23 of 37 OTHER ELASTICITIES OF DEMAND 4.5 Cross-Price Elasticity of Demand cross-price elasticity of demand A measure of the responsiveness of demand to changes in the price of another good; equal to the percentage change in the quantity demanded of one good (X) divided by the percentage change in the price of another good (Y).

24. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 24 of 37 HIGH FUEL PRICES IMPACT VACATION PLANS Memorial Day vacation travel by automobile will be up by only 0.7 percent this year, the smallest increase in several years. A 34 percent year-to-year increase in the price of gasoline is the culprit. The AAA Travel survey also indicated that many vacationers would alter their plans to take advantage of cheaper motels, closer destinations, and/or shorter stays. The substitution effect helps explain why the demand curve is downward sloping and to the right. As the price of gasoline increases people will alter their behavior by buying less gasoline. Part of this behavior can be explained by consumers substituting a portion of gasoline purchases. Vacation and entertainment travel happens to be a substitutable component of gasoline consumption. Extra Application 9 Air, bus, and train travel all expect similar slight increases in people traveling, or stable numbers. Airplane ticket prices are up about 10 percent and hotels have increased rates by about 5 percent.

25. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 25 of 37 THE PRICE ELASTICITY OF SUPPLY 4.6 price elasticity of supply A measure of the responsiveness of the quantity supplied to changes in price; equal to the percentage change in quantity supplied divided by the percentage change in price.

26. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 26 of 37 THE PRICE ELASTICITY OF SUPPLY 4.6 FIGURE 4.3 The Slope of the Supply Curve and Supply Elasticity

27. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 27 of 37 THE PRICE ELASTICITY OF SUPPLY 4.6 What Determines the Price Elasticity of Supply? The price elasticity of supply is determined by how rapidly production costs increase as the total output of the industry increases. If the marginal cost increases rapidly, the supply curve is relatively steep and the price elasticity is relatively low.

28. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 28 of 37 THE PRICE ELASTICITY OF SUPPLY 4.6 The Role of Time: Short-Run Versus Long-Run Supply Elasticity Time is an important factor in determining the price elasticity of supply for a product. The market supply curve is positively sloped because of two responses to an increase in price: Short run. A higher price encourages existing firms to increase their output by purchasing more materials and hiring more workers. Long run. New firms enter the market and existing firms expand their production facilities to produce more output. The short-run response is limited because of the principle of diminishing returns.

29. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 29 of 37 THE PRICE ELASTICITY OF SUPPLY 4.6 Extreme Cases: Perfectly Inelastic Supply and Perfectly Elastic Supply FIGURE 4.4 Perfectly Inelastic Supply and Perfectly Elastic Supply

30. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 30 of 37 THE MARKET FOR RARE GUITARS The price of rare guitars is escalating faster than most corporate stocks. A sunburst Les Paul Standard that originally sold for $265 in 1960 can now command $300,000 in pristine condition. Les Pauls are not alone in this market. Pre-war Martin acoustic guitars and pre- 1966 Fender Stratocasters have seen similar run-ups. Much of the recent price appreciation has been driven by non-musician investors attempting to cash in on the gains. However, scarcity is also to blame. For example, there were only approximately 1,700 sunburst Les Pauls ever manufactured. Many experts caution buyer beware since the astronomical prices have stimulated a heavy trade in fakes. The current estimated count of 2,200 sunburst Les Pauls illustrates this point. Where did the other 500 come from? The known supply of rare guitars is virtually fixed. Therefore, increasing demand by collectors pushes the price rapidly higher. Even a very small shift in demand due to an increase in the number of collectors/investors results in a substantial change in the price. The opposite is also true. If investor/collectors suddenly became concerned about this market and moved into other investments (i.e. decrease in the number of potential buyers) the price could fall just as rapidly. Extra Application 11

31. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 31 of 37 THE PRICE ELASTICITY OF SUPPLY 4.6 Extreme Cases: Perfectly Inelastic Supply and Perfectly Elastic Supply perfectly inelastic supply The price elasticity of supply equals zero. perfectly elastic supply The price elasticity of supply is equal to infinity. Predicting Changes in Quantity Supplied

32. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 32 of 37 OPECS OIL STRANGLEHOLD The Organization of Petroleum Exporting Countries (OPEC) is considering production cutbacks to halt the falling world price of oil. However, OPEC members are also cognizant of the fact that high oil prices spur development of alternative fuel sources. Many analysts point out that this fact forces OPEC to allow prices to fall periodically so that alternative fuel projects do not become viable. However, as oil demand continues to increase, OPEC may not be able to periodically lower prices. Since oil has a relatively inelastic short run demand, a cutback in supply results in only a very small reduction in the number of units sold but a substantial increase in price. Since the production and distribution costs will remain constant the price increase means a significant increase in profits for oil producers. Extra Application 10

33. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 33 of 37 USING ELASTICITIES TO PREDICT CHANGES IN EQUILIBRIUM PRICE 4.7 The Price Effects of a Change in Demand FIGURE 4.5 An Increase in Demand Increases the Equilibrium Price

34. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 34 of 37 USING ELASTICITIES TO PREDICT CHANGES IN EQUILIBRIUM PRICE 4.7 The Price Effects of a Change in Demand Under what conditions will an increase in demand cause a relatively small increase in price? Small increase in demand. Highly elastic demand. Highly elastic supply.

35. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 35 of 37 USING ELASTICITIES TO PREDICT CHANGES IN EQUILIBRIUM PRICE 4.7 The Price Effects of a Change in Supply FIGURE 4.6 A Decrease in Supply Increases the Equilibrium Price

36. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 36 of 37 USING ELASTICITIES TO PREDICT CHANGES IN EQUILIBRIUM PRICE 4.7 The Price Effects of a Change in Supply Under what conditions will a decrease in supply cause a relatively small increase in price? Small decrease in supply. Highly elastic demand. Highly elastic supply.

37. chapter © 2007 Pearson/Prentice Hall, Survey of Economics: Principles, Applications & Tools, 3e, OSullivan Sheffrin Perez 37 of 37 AN IMPORT BAN AND SHOE PRICES APPLYING THE CONCEPTS #7: How do import restrictions affect prices? We can use the supply version of the price-change formula to predict the effects of import restrictions on equilibrium prices. Consider a nation that limits shoe imports. Suppose the import restrictions decrease the supply of shoes by 30 percent. To use the price-change formula, we need the price elasticities of supply and demand. Suppose the supply elasticity is 2.3 and, as shown in Table 20.2, the demand elasticity is 0.70. Plugging these numbers into the price-change formula, we predict a 10-percent increase in price: