Answers to the Problems and Applications

A n s w e r s t o t h e P r o b l e m s a n d A p p l i c a t i o n s1. Brazil produces ethanol from sugar,

and the land used to grow sugar can be used to grow food crops. Suppose that Brazil’s production possibilities for ethanol and food crops are given in the table.

a. Draw a graph of Brazil’s PPF and explain how your graph illustrates scarcity.

Figure 2.1 shows Brazil’s PPF. The production possibilities frontier itself indicates scarcity because it shows the limits to what can be produced. In particular, production combinations of ethanol and food crops that lie beyond the production possibilities frontier are not attainable.

b. If Brazil produces 40 barrels of ethanol a day, how much food must it produce if it achieves production efficiency?

If Brazil produces 40 barrels of ethanol per day, it achieves production efficiency if it also produces 3 tons of food per day.

c. Why does Brazil face a tradeoff on its PPF?

Brazil faces a tradeoff on its PPF because Brazil’s resources and technology are limited. For Brazil to produce more of one good, it must shift factors of production away from the other good. Therefore to increase production of one good requires decreasing production of the other good, which reflects a tradeoff.

d. If Brazil increases its production of ethanol from 40 barrels per day to 54 barrels per day, what is the opportunity cost of the additional ethanol?

When Brazil is production efficient and increases its production of ethanol from 40 barrels per day to 54 barrels per day, it must decrease its production of food crops from 3 tons per day to 2 tons per day. Hence the opportunity cost of the additional ethanol is 1 ton of food per day for the entire 14 barrels of ethanol or 1/14 of a ton of food per barrel of ethanol.

e. If Brazil increases its production of food crops from 2 tons per day to 3 tons per day, what is the opportunity cost of the additional food?

When Brazil is production efficient and increases its production of food crops from 2 tons per day to 3 tons per day, it must decrease its production of ethanol from 54 barrels per day to 40 barrels per day. Hence the opportunity cost of the additional 1 ton of food crops is 14 barrels of ethanol.

Ethanol(barrels per

day)

Food crops(tons per

day)70 an

d0

64 and

1

54 and

2

40 and

3

22 and

4

0 and

5

f. What is the relationship between your answers to d and e?The opportunity costs are reciprocals of each other. That is, the opportunity cost of 1 ton of food crops is 14 barrels of ethanol and the opportunity cost of 1 barrel of ethanol is 1/14 of a ton of food crops.

g. Does Brazil face an increasing opportunity cost of ethanol? What feature of the PPF that you’ve drawn illustrates increasing opportunity cost?

Brazil faces an increasing opportunity cost of ethanol production. For instance, when increasing ethanol production from 0 barrels per day to 22 barrels the opportunity cost of a barrel of ethanol is 1/22 of a ton of food while increasing ethanol production another 18 barrels per day (to a total of 40 barrels per day) has an opportunity cost of 1/18 of a ton of food per barrel of ethanol. The PPF’s bowed outward shape reflects the increasing opportunity cost.

2. Define marginal cost and use the information provided in the table in problem 1 to calculate the marginal cost of producing a ton of food when the quantity produced is 2.5 tons per day.

The marginal cost of a good is the opportunity cost of producing one more unit of the good. When the quantity of food produced is 2.5 tons, the marginal cost of a ton of food is the opportunity cost of increasing the production of food from 2 tons per day to 3 tons per day. If this increase is carried out, the production of ethanol falls 54 barrels per day to 40 barrels per day, a decrease of14 barrels per day. The opportunity cost of increasing food production is the decrease in ethanol product, so the opportunity cost of producing a ton of food when 2.5 tons of food per day are produced is 14 barrels of ethanol per day.

3. Define marginal benefit, explain how it is measured, and explain why the information provided in the table in problem 1 does not enable you to calculate the marginal benefit of food.

The marginal benefit of a good is the benefit received from consuming one more unit of the product. The marginal benefit of a good or service is measured by the most people are willing to pay for one more unit of it. The data in the table do not provide information on how much people are willing to pay for an additional unit of food. Hence the table has no information on the marginal benefit of food.

4. Distinguish between production efficiency and allocative efficiency. Explain why many production possibilities achieve production efficiency but only one achieves allocative efficiency.

Production efficiency occurs when goods and services are produced at the lowest cost. This definition means that production efficiency occurs at any point on the PPF. Therefore all of the production points on the PPF are production efficient. Allocative efficiency occurs when goods and services are produced at the lowest cost and in the quantities that provide the greatest possible benefit. The allocatively efficient production point is the single point on the PPF that has the greatest possible benefit.

5. Harry enjoys tennis but wants a high grade in his economics course. Figure 2.2 shows the limits to what he can achieve: It is Harry’s PPF for these two “goods.” Figure 2.3 (on the next page) shows Harry’s MB curve for tennis.

a. What is Harry’s marginal cost of tennis if he plays for (i) 3 hours a week; (ii) 5 hours a week; and (iii) 7 hours a week.

(i) Harry’s marginal cost of an hour of tennis is 1.5 percentage points. When Harry increases the time he plays tennis from 2 hours to 4 hours, his grade in economics falls from 78 percent to 75 percent. His opportunity cost of these 2 additional hours of tennis is 3 percentage points, so his marginal cost of playing tennis for the third hour per week is 1.5 percentage points. (ii) Harry’s marginal cost of an hour of tennis is 2.5 percentage points. When Harry increases the time he plays tennis from 4 hours to 6 hours, his grade in economics falls from 75 percent to 70 percent. His opportunity cost of these 2 additional hours of tennis is 5 percentage points. So his marginal cost of playing tennis for the fifth hour per week is 2.5 percentage points. (iii) Harry’s marginal cost of an hour of tennis is 5 percentage points. When Harry increases the time he plays tennis from 6 hours to 8 hours, his grade in economics falls from 70 percent to 60 percent. His opportunity cost of these 2 additional hours of tennis is 10 percentage points. So his marginal cost of playing tennis for the seventh hour per week is 5 percentage points.

b. If Harry uses his time to achieve allocative efficiency, what is his economics grade and how many hours of tennis does he play?

Harry’s grade in economics is 66 percent and he plays tennis for 7 hours per week. From the answer to part (a), Harry’s marginal cost of playing the third hour a week of tennis is 1.5 percentage points, his marginal cost of playing tennis the fifth hour a week is 2.5 percentage points and his marginal cost of playing tennis the seventh hour a week is 5 percentage points. Plot these three opportunity costs in Figure 2.3 to create Harry’s marginal cost curve. Harry’s opportunity cost of playing tennis increases as he spends more time on tennis. Harry uses his time efficiently if he plays tennis for 7 hours a week because when he plays 7 hours a week his marginal benefit from the seventh hour of tennis, 5 percentage points, equals its marginal cost, also 5 percentage points. When Harry plays 7 hours of tennis, the PPF in Figure 2.2 shows that his grade in economics 66 percent.

c. Explain why Harry would be worse off getting a grade higher than your answer to b.

If Harry studied for enough hours to get a higher grade, he would have fewer hours to play tennis. Harry’s marginal benefit from tennis would be greater than his marginal cost, so he would be more efficient (better off) if he played more hours of tennis and took a lower grade.

d. If Harry becomes a tennis superstar with big earnings from tennis, what happens to his PPF, MB curve, and efficient time allocation?

If Harry becomes a tennis superstar, his PPF does not change. Harry’s PPF shows the grade he can produce for different hours of playing tennis and these production possibilities are unaffected by Harry’s superstar status. As a result Harry’s MC curve does not change. However Harry’s MB from playing tennis increases because of his big paydays so his MB curve shifts rightward. As a result, Harry’s efficient allocation of time now allocates more time to tennis (and results in a lower grade).

e. If Harry suddenly finds high grades in economics easier to attain, what happens to his PPF, MB curve, and efficient time allocation?

If Harry finds high grades to easier to attain his PPF shifts outward. In particular for every level of tennis playing his grade in economics is higher. As a result Harry’s marginal cost of earning a high grade in economics is reduced so that Harry’s MC curve shifts downward. Harry’s MB curve does not change because Harry’s marginal benefit from a high grade has not changed. Harry’s efficient time allocation results in Harry increasing the number of hours of tennis he plays.

6. A farm grows wheat and produces pork. The marginal cost of producing each of these products increases as more of it is produced.

a. Make a graph that illustrates the farm’s PPF.

The PPF is illustrated in Figure 2.4 as PPF0. Because the marginal cost of both wheat and pork increase as more of the product is produced, the PPF displays increasing opportunity cost so it has the “conventional” bowed outward shape.

b. The farm adopts a new technology that allows it to use fewer resources to fatten pigs. Use your graph to illustrate the impact of the new technology on the farm’s PPF.

The new technology rotates the PPF outward from PPF0 to PPF1.

c. With the farm using the new technology described in b, has the opportunity cost of producing a ton of wheat increased, decreased, or remained the same? Explain and illustrate your answer.

The opportunity cost of producing wheat has increased. The opportunity cost of a bushel of wheat is equal to the magnitude of the slopes of the PPFs illustrated in Figure 2.4. The slope of PPF1 has a larger magnitude than the slope of PPF0 so the opportunity cost of a bushel of wheat is higher along PPF1. Alternatively, the opportunity cost of increasing wheat product from 600 bushels per week to 800 bushels per week along PPF1 is 35 hundred pounds of pork but is only 20 hundred pounds of pork along PPF0.

d. Is the farm more efficient with the new technology than it was with the old one? Why?

The farm is able to produce more with the new technology than with the old, but it is not necessarily more efficient. If the farm was producing on its PPF before the new technology and after, the farm was production efficient both before the new technology and after.

7. In one hour, Sue can produce 40 caps or 4 jackets and Tessa can produce 80 caps or 4 jackets.

a. Calculate Sue’s opportunity cost of producing a cap.Sue forgoes 4 jackets to produce 40 caps, so Sue’s opportunity cost of producing one cap is (4 jackets)/(40 caps) or 0.1 jacket per cap.

b. Calculate Tessa’s opportunity cost of producing a cap.Tessa forgoes 4 jackets to produce 80 caps, so Tessa’s opportunity cost of producing one cap is (4 jackets)/(80 caps) or 0.05 jacket per cap.

c. Who has a comparative advantage in producing caps?Tessa’s opportunity cost of a cap is lower than Sue’s opportunity cost, so Tessa has a comparative advantage in producing caps.

d. If Sue and Tessa specialize in producing the good in which each of them has a comparative advantage, and they trade 1 jacket for 15 caps, who gains from the specialization and trade?

Tessa specializes in caps and Sue specializes in jackets. Both Sue and Tessa gain from trade. Sue gains because she can obtain caps from Tessa at a cost of (1 jacket)/(15 caps), which is 0.067 jacket per cap, a cost that is lower than what it would cost her to produce caps herself. Tessa also gains from trade because she trades caps for jackets for 0.067 jacket per cap, which is higher than her cost of producing a cap.

8 Suppose that Tessa buys a new machine for making jackets that enables her to make 20 jackets an hour. (She can still make only 80 caps per hour.)

a. Who now has a comparative advantage in producing jackets?Sue forgoes 40 caps to produce 4 jackets, so Sue’s opportunity cost of producing one jacket is (40 caps)/(4 jackets) or 10 caps per jacket. Tessa forgoes 80 caps to produce 20 jackets, so Tessa’s opportunity cost of producing one jacket is (80 caps)/(20 jackets) or 4 caps per jacket. Tessa has the comparative advantage in producing jackets because her opportunity cost of a jacket is lower than Sue’s opportunity cost.

b. Can Sue and Tessa still gain from trade?Tessa and Sue can still gain from trade because Tessa (now) has a comparative advantage in producing jackets and Sue (now) has a comparative advantage in producing caps. Tessa will produce jackets and Sue will produce caps.

c. Would Sue and Tessa still be willing to trade 1 jacket for 15 caps? Explain your answer.

Sue and Tessa will not be willing to trade 1 jacket for 15 caps. In particular, Sue, whose comparative advantage lies in producing caps, can produce 1 jacket at an opportunity cost of only 10 caps. So Sue will be unwilling to pay any more than 10 caps per jacket.

9. “America’s baby-boomers are embracing tea for its health benefits,” said The Economist (July 8, 2005, p. 65). The article went on to say: “Even though the climate is suitable, tea-growing [in the United States] is simply too costly, since the process is labor-intensive and resists automation.” Using this information:

a. Sketch a PPF for the production of tea and other goods and services in India.

The PPF might be linear, though a more realistic PPF would be bowed out from the origin. The products along the two axes are tea and other goods and services. In Figure 2.5, tea is drawn along the horizontal axis but it could also be drawn along the vertical axis.

b. Sketch a PPF for the production of tea and other goods and services in the United States.

Again the PPF might be linear, though a more realistic PPF would be bowed out from the origin. As before, the

products along the two axes are tea and other goods and services. Figure 2.6 (on the next page) illustrates the situation in the United States. Compared to India, the important point about the two PPFs is that the opportunity cost of producing tea is lower in India. If tea is measured along the horizontal axis, the magnitude of the slope of the PPF is equal to the opportunity cost of producing tea, so in this case the U.S. PPF would be steeper than the Indian PPF. If tea is measured along the vertical axis, then the Indian PPF would be steeper than the U.S. PPF.

c. Sketch a marginal cost curve for the production of tea in India.

The marginal cost curve for producing tea in India is illustrated in Figure 2.7. This marginal cost curve slopes upward.

d. Sketch a marginal cost curve for the production of tea in the United States.

The marginal cost curve for producing tea in the United States is also illustrated in Figure 2.7. Similar to the marginal cost curve for India, the U.S. marginal cost curve slopes upward. Because tea is less costly to produce in India than in the United States, the U.S. MC curve lies above the Indian MC curve.

e. Sketch the marginal benefit curve for tea in the United States before and after the baby boomers began to appreciate the health benefits of tea.

As Figure 2.8 shows, the downward sloping marginal benefit curve for tea shifts rightward after more baby-boomers start to appreciate tea.

f. Explain why the United States does not produce tea and instead imports it from India.

The United States imports tea from India because it is cheaper for the U.S. to import tea than to produce it in the United States. Fewer other goods and services must be given up to import tea than would be given up if the United States produced tea.

g. Explain how the quantity of tea that achieves allocative efficiency has changed.

The increase in the marginal benefit from tea increases the quantity of tea that achieves allocative efficiency.

e. Does the change in preferences toward tea affect the opportunity cost of producing tea?

If the PPF in India between tea and other goods and services is bowed out from the origin, increasing the production of tea raises the opportunity cost of producing tea.

10. Brazil produces ethanol from sugar at a cost of 83 cents per gallon. The United States produces ethanol from corn at a cost of $1.14 per gallon. Sugar grown on one acre of land produces twice the quantity of ethanol as the corn grown on an acre. The United States imports 5 percent of its ethanol consumption and produces the rest itself. Since 2003, U.S. ethanol production has more than doubled and U.S. corn production has increased by 45 percent.

a. Does Brazil or the United States have a comparative advantage in producing ethanol?

Brazil has a comparative advantage in producing ethanol. In Brazil $0.83 worth of other goods and services must be forgone to produce a gallon of ethanol whereas in the United States $1.14 of other goods and services must be forgone to produce a gallon of ethanol.

b. Do you expect the opportunity cost of producing ethanol in the United States to have increased since 2003? Explain why.

If there have been no technological changes in the production of ethanol, so that the PPF between ethanol and other goods and services has not shifted, then the opportunity cost of producing ethanol in the United States increased as more ethanol was produced.

c. Sketch the PPF for ethanol and other goods and services for the United States.

Figure 2.9 shows the U.S. PPF. For simplicity and in keeping with Figure 2.6 on p. 42 of the textbook, the PPF is linear.

d. Sketch the PPF for ethanol and other goods and services for Brazil.Figure 2.10 shows the Brazilian PPF. For simplicity and in keeping with the Figure on p. 42 of the textbook, the PPF is linear.

e. Sketch a figure similar to Fig. 2.6 on p. 42 to show how both the United States and Brazil can gain from specialization and trade.

In general, the United States gains from trade with Brazil by importing ethanol from Brazil. Brazil produces ethanol at a lower opportunity cost than the United States, so the opportunity cost to the United States of consuming ethanol is lower if the United States consumes ethanol produced in Brazil. In Figure 2.9 initially the United States produced and consumed 400 billion units of other goods and services and 10 million gallons of ethanol. After specializing in the production of other goods and services and trading with Brazil, the United States produces 800 billion units of other goods and services. By trading 200 billion units of goods and services for 20 million gallons of ethanol, the United States consumes 600 billion units of other goods and services and 20 million gallons of ethanol. The consumption of both other goods and services and ethanol increases in the United States. The story in Brazil is similar. In Figure 2.10 prior to trade Brazil produced and consumed billion units of other goods and services and 20 million gallons of ethanol. After specializing in the production of ethanol (50 million gallons of ethanol) and trading with the United States (20 million gallons of ethanol in exchange for 200 billion units of other goods and services) Brazil consumes 200 billion units of other goods and services and 30 million gallons of ethanol. The consumption of both other goods and services and ethanol increases in Brazil.

f. Do you think the United States has achieved production efficiency in its manufacture of ethanol? Explain why or why not.

The United States has probably attained production efficiency. In the United States firms have the incentive to produce goods and services, such as

ethanol, efficiently because the owners of firms have been given the property right to their firm’s profit.

g. Do you think the United States has achieved allocative efficiency in its manufacture of ethanol? Explain why or why not.

With the higher price of gasoline, the demand for ethanol and, as a result, the demand for the corn used to produce ethanol increased. The allocatively efficient quantity of both have increased. However the United States does not allow free trade in ethanol, which is why the U.S. price exceeds the Brazilian price. It is likely that the allocatively efficient quantity of U.S.-produced ethanol is less than the quantity actually produced in the United States. Most likely allocative efficiency requires that the United States should produce less ethanol, more other goods and services, and trade with Brazil because Brazil produces ethanol at lower cost than the United States.

11. For 50 years, Cuba has had a centrally planned economy in which the government makes the big decisions on how resources will be allocated. Why would you expect Cuba’s production possibilities (per person) to be smaller than those of the United States? What are the economic institutions that help the U.S. economy achieve allocative efficiency that Cuba might lack?

Cuba’s economy is almost surely less efficient than the U.S. economy. Because owners of firms in the United States have been given the property rights to any profit their firm might earn, owners have the self-interested incentive to operate the firm efficiently and produce goods and services that consumers desire. In Cuba these incentives are absent because firms are not privately owned. As a result, no single person has the self-interested incentive to either insure that firms produce goods and services efficiently or produce the goods and services that consumers desire. In other words, the U.S. economy with its property rights and markets has harnessed people’s self interest to produce goods and services efficiently and so the U.S. economy is likely much closer to allocative efficiency than is the Cuban economy.

12. Suppose that Yucatan’s production possibilities are given in the table.

a. Draw a graph of Yucatan’s PPF and explain how your graph illustrates a tradeoff.

Yucatan’s PPF is illustrated in Figure 2.11 (on the next page). The figure illustrates a tradeoff because moving along Yucatan’s PPF producing more of one good requires producing less of the other good. Yucatan trades off more production of one good for less production of the other.

Food(pounds

per month)

Sunscreen(gallons

per month)

300 and

0

200 and

50

100 and

100

0 and

150

b. If Yucatan produces 150 pounds of food per month, how much sunscreen must it produce if it achieves production efficiency?

If Yucatan produces 150 pounds of food per month, then the point labeled A on the PPF in Figure 2.11 shows that Yucatan must produce 75 gallons of sunscreen per month to achieve production efficiency.

c. What is Yucatan’s opportunity cost of producing 1 pound of food?

Yucatan’s PPF is linear so the opportunity cost of producing 1 pound of food is the same at all quantities. Calculate the opportunity cost of producing 1 pound of food when moving from 0 to 100 pounds per month. Between these two ranges of production, the quantity of sunscreen produced falls from 150 gallons per month to 100 gallons per month, a decrease of 50 gallons. The opportunity cost is 50 gallons of sunscreen to gain 100 pounds of food. The opportunity cost per pound of food equals (50 gallons of sunscreen)/(100 pounds of food), or an opportunity cost of 0.5 gallons of sunscreen per pound of food.

d. What is Yucatan’s opportunity cost of producing 1 gallon of sunscreen?Yucatan’s PPF is linear so the opportunity cost of producing 1 gallon of sunscreen is the same at all quantities. Calculate the opportunity cost of producing 1 gallon of sunscreen moving from 0 to 50 gallons per month. Between these two ranges of production, the quantity of food produced falls from 300 pounds per month to 200 pounds per month, a decrease of 100 pounds. The opportunity cost is 100 pounds of food in order to gain of 50 gallons of sunscreen, or (100 pounds of food)/(50 gallons of sunscreen) which yields an opportunity cost of 2.0 pounds of food per gallon of sunscreen.

e. What is the relationship between your answers to c and d?Answers c and d reflect the fact that opportunity cost is a ratio. The opportunity cost of gaining a unit of a product moving along the PPF equals the quantity of the other good or service forgone divided by the quantity of the good or service gained. The opportunity cost of one good, food, is equal to the inverse of the opportunity cost of the other good, sunscreen.

f. Does Yucatan face an increasing opportunity cost of food? What feature of a PPF illustrates increasing opportunity cost and why does the PPF that you have drawn not have this feature?

Yucatan does not face an increasing opportunity cost of food because the opportunity cost remains constant, equal to 0.5 gallons of sunscreen per pound of food. If opportunity costs increase, the PPF bows outward. Yucatan’s PPF is linear and along a linear PPF the opportunity cost is constant.

13. What is the marginal cost of a pound of food in Yucatan in problem 12 when the quantity produced is 150 tons per day? What is special about the marginal cost of food in Yucatan?

The marginal cost of a pound of food in Yucatan is constant at all points along Yucatan’s PPF and is equal to 0.5 gallons of sunscreen per pound of food. The

special point about Yucatan’s marginal cost is the fact that the marginal cost is constant.

14. In Yucatan, which has the production possibilities shown in the table in problem 12, preferences are described by the table.

a. What is the marginal benefit from sunscreen, how it is measured?

The marginal benefit from sunscreen is the benefit enjoyed by the person who consumes one more gallon of sunscreen. It is equal to the willingness to pay for an additional gallon.

b. What information provided in the table above and the table in problem 12 do we need to be able to calculate the marginal benefit from sunscreen in Yucatan?

The table gives the information necessary to calculate the marginal benefit from sunscreen. The marginal benefit is equal to the willingness to pay for a gallon of sunscreen.

c. Draw a graph of Yucatan’s marginal benefit from sunscreen.

To draw the marginal benefit from sunscreen, plot the quantity of sunscreen on the x-axis and the willingness to pay for sunscreen (that is, the number of pounds of food that they are willing to give up to get a gallon of sunscreen) on the y-axis. Figure 2.12 shows this figure.

15. “Dr. Arata Kochi, the World Health Organization malaria chief, ... [says that] eradication is counterproductive. With enough money, he said, current tools like nets, medicines and DDT could drive down malaria cases 90 percent. ‘But eliminating the last 10 percent is a tremendous task and very expensive,’ Dr. Kochi said. ‘Even places like South Africa should think twice before taking this path.’”

The New York Times, March 4, 2008

Sunscreen(gallons

per month)

Willingness to pay

(pounds per gallon)

25 and

3

75 and

2

125 and

1

a. Is Dr. Kochi talking about production efficiency or allocative efficiency or both?

Dr. Kochi is talking about allocative efficiency. His assessment is that the last 10 percent eradication has such a high marginal cost that it almost surely exceeds its marginal benefit.

b. Make a graph with the percentage of malaria cases eliminated on the x-axis and the marginal cost and marginal benefit of driving down malaria cases on the y-axis. On your graph:(i) Draw a marginal cost curve that is consistent with Dr. Kochi’s

opinion reported in the news article.(ii) Draw a marginal benefit curve that is consistent with Dr. Kochi’s

opinion reported in the news article.(iii) Identify the quantity of malaria eradicated that achieves allocative

efficiency.Figure 2.13 shows a marginal cost curve and a marginal benefit curve that are consistent with Dr. Kochi’s views. The marginal cost curve rises rapidly after 90 percent of malaria is eradicated. The allocatively efficient quantity of malaria eradicated is 90 percent because that is the quantity for which the marginal benefit of eradication equals the marginal cost of eradication.

16. Capital accumulation and technological change bring economic growth, which means that the PPF keeps shifting outward: Production that was unattainable yesterday becomes attainable today; and production that is unattainable today will become attainable tomorrow. Why doesn’t this process of economic growth mean that scarcity is being defeated and will one day be gone?

Scarcity is always being defeated yet will never suffer defeat. Scarcity reflects the existence of unmet wants. People’s wants are infinite—regardless of what a person already possesses, everyone can easily visualize something else he or she wants, if only more time in the day to enjoy their possessions. Because people’s wants are insatiable, scarcity will always exist regardless of economic growth.

17. “Inexpensive broadband access has done far more for online video than enable the success of services like YouTube and iTunes. By unchaining video watchers from their TV sets, it has opened the floodgates to a generation of TV producers for whom the Internet is their native medium.”

The New York Times, December 2, 2007

a. How has inexpensive broadband changed the production possibilities of video entertainment and other goods and services?

Inexpensive broadband has increased the production possibilities.

b. Sketch a PPF for video entertainment and other goods and services before broadband.

The PPF should have video entertainment on one axis and other goods and services on the other as illustrated in Figure 2.14 by PPF0. The PPF is bowed outward as a conventional PPF.

c. Show how the arrival of inexpensive broadband has changed the PPF.

The arrival of inexpensive broadband shifts the PPF outward as shown by the change from PPF0 to PPF1 in Figure 2.14. The intersection of the new PPF along the axis measuring video entertainment increases and the intersection of the new PPF along the axis measuring other goods and services does not change.

d. Sketch a marginal benefit curve for video entertainment.The marginal benefit curve should be a conventional downward sloping marginal benefit curve as shown in Figure 2.15. The marginal benefit from video entertainment is measured along the vertical axis and the quantity of video entertainment is measured along the horizontal axis.

e. Show how opening the “floodgates to a generation of TV producers for whom the Internet is their native medium” might have changed the marginal benefit from video entertainment.

The marginal benefit curve does not shift because of “opening the floodgates” since this effect changes the marginal cost not the marginal benefit. The marginal cost curve shifts downward. However if there is increased excitement about this medium, then the marginal benefit increases and the marginal benefit curve shifts rightward. Then, as illustrated in Figure 2.16 the allocatively efficient quantity of video entertainment increases.

f. Explain how the quantity of video entertainment that achieves allocative efficiency has changed.

Because the marginal cost of providing video entertainment falls, the allocatively efficient quantity of video entertainment increases, in Figure 2.16 from 5 million units per year to 8 million units per year.

18. Kim can produce 40 pies an hour or 400 cookies an hour. Liam can produce 100 pies an hour or 200 cookies an hour.

a. Calculate Kim’s opportunity cost of producing a pie.If Kim spends an hour baking pies, she gains 40 pies but forgoes 400 cookies. Kim’s opportunity cost of 1 pie is (400 cookies)/(40 pies), or 10 cookies per pie.

b. Calculate Liam’s opportunity cost of producing a pie.If Liam spends an hour baking pies, he gains 100 pies but forgoes 200 cookies. Liam’s opportunity cost of 1 pie is (200 cookies)/(100 pies), or 2 cookies per pie.

c. Who has a comparative advantage in producing pies?Liam has the comparative advantage in producing pies because his opportunity cost of a pie is less than Kim’s opportunity cost.

d. If Kim and Liam spend 30 minutes of each hour producing pies and 30 minutes producing cookies, how many pies and cookies does each of them produce?

Kim produces 20 pies and 200 cookies. Liam produces 50 pies and 100 cookies. The total number produced is 70 pies and 300 cookies.

e. Suppose that Kim and Liam increase the time they spend producing the good in which they have a comparative advantage by 15 minutes. What will be the increase in the total number of pies and cookies they produce?

Kim spends her 15 minutes producing more cookies and Liam spends his 15 minutes producing pies. Kim produces 300 cookies and 10 pies, while Liam produces 75 pies and 50 cookies. The total number of pies and cookies produced is 85 pies and 350 cookies, an increase of 15 pies and 50 cookies over the situation described in part d.

f. What is the highest price of a pie at which Kim and Liam would agree to trade pies and cookies?

Liam will trade pies to Kim in exchange for cookies. The highest price for a pie at which Kim is willing to trade is 10 cookies per pie. If the price were any higher, it would be cheaper for Kim if she produced her own pies. Kim will trade cookies to Liam in exchange for pies. The highest price for a cookie at which Liam is willing to trade is 0.5 pies per cookie. (This price is Liam’s opportunity cost of a cookie.) If the price were any higher, it would be cheaper for Liam if he produced her own cookies.

g. If Kim and Liam specialize and trade, what are the gains from trade?Kim will specialize in cookies and Liam will produce pies. If they specialize and trade, the total production of both cookies and pies increase. This increase is the gains from trade.

19. Before the Civil War, the South traded with the North and with England. The South sold cotton and bought manufactured goods and food. During the war, one of Lincoln’s first actions was to blockade the ports, which prevented this trade. The South had to increase its production of munitions and food.

a. In what did the South have a comparative advantage?Before the war the South had a comparative advantage in producing cotton.

b. Draw a graph to illustrate production, consumption, and trade in the South before the Civil War.

Figure 2.17 illustrates the South’s situation. The production point is point a. The South produces a great deal of cotton and very little food and manufactured goods; indeed, in the unlikely case that the South completely specialized, the production point could be at the maximum quantity of cotton and zero food and manufactured goods. From the production point a trade line with a negative slope touches the PPF and extends beyond the PPF. The trade line shows that the South traded cotton for manufacturing goods and food and consumed at point b, well beyond its PPF.

c. Was the South consuming inside, on, or outside its PPF? Explain your answer.

The South was consuming at a point beyond its PPF. The South could do so because it was able to trade cotton, which was relatively less expensive for the South to produce, in exchange for manufactured goods and food, which would have been relatively expensive for the South to produce. In other words, the South enjoyed gains from trade.

d. Draw a graph to show the effects of the Civil War on consumption and production in the South.

Assuming that the Civil War did not affect the South’s PPF (which is probably true only for the first part of the war) the North’s blockade meant that the South could no longer trade with others. As a result, the South increased its production of manufactured goods (especially munitions) and food, which caused the South to decrease its production of cotton. The blockade forced the South’s consumption point to lie on its PPF, so the South’s consumption of manufactured goods and food decreased. In Figure 2.17, the South changes so that its production and its consumption point become point c.

e. Did the Civil War change any opportunity costs in the South? Did the opportunity cost of everything rise? Did any items cost less?

The Civil War increased the opportunity cost of food and manufactured goods. However it decreased the opportunity cost of cotton.

f. Illustrate your answer to e with appropriate graphs.Figure 2.17 illustrates the changes. The opportunity cost of cotton decreased because the blockade lead the South to produce less cotton, moving from initial production point a to final production point c. Moving along a PPF, as less of a good is produced, its opportunity cost falls. The opportunity cost of

food and manufactured goods increased because the South increased the amount of food and manufactured goods it produced. Moving along a PPF, as more of a good is produced, its opportunity cost rises.

20. “A two-time N.B.A. All-Star, Barron Davis has quietly been moonlighting as a [movie] producer since 2005, when he and a high school buddy, Cash Warren, formed a production company called Verso Entertainment. In January, Verso’s first feature-length effort, “Made in America,” a gang-life documentary directed by Stacy Peralta, had its premiere to good reviews at Sundance Film Festival and is being courted by distributors.”

The New York Times, February 24, 2008a. Does Barron Davis have an absolute advantage in basketball and movie

directing and is this the reason for his success in both activities?Mr. Davis might have an absolute advantage in both endeavors. His success, however, is the result of his comparative advantage in both.

b. Does Barron Davis have a comparative advantage in basketball or movie directing or both of them and is this the reason for his success in both activities?

Mr. Davis has many activities available, so he might have a comparative advantage in both basketball and directing. Mr. Davis, however, will not have a comparative advantage in all the other activities.

c. Sketch a PPF between playing basketball and producing other goods and services for Barron Davis and for yourself.

Figure 2.18 shows a typical set of PPFs. Unless the student is a future NBA superstar, the PPF for Mr. Davis will definitely intersect the axis that measures playing basketball much farther away from the origin than the student’s PPF. The intersection of the PPF and the axis that measures the production of other goods might be higher for Mr. Davis or might be higher for the student (depending on the student’s ego). But the student’s PPF will be steeper than Mr. Baron’s PPF, indicating that the opportunity cost of producing units of basketball is lower for Mr. Davis than for the student.

d. How do you (and people like you) and Barron Davis (and people like him) gain from specialization and trade?

Mr. Davis will specialize in the activity in which he has a comparative advantage, possibly playing basketball. Other people will specialize in the activities in which they have comparative advantages. As a result, production of all goods and services takes place at the lowest opportunity costs. Then all these low-cost producers can trade with everyone else, so that everybody can enjoy a richer and more complex consumption bundle acquired at lower cost than if the goods and services were produced by the person himself or herself.

21. After you have studied Reading Between the Lines on pp. 46–47, answer the following questions:

a. How has an Act of the United States Congress increased U.S. production of corn?

The Act of Congress increased the amount of ethanol that must be used in gasoline. Because ethanol is made from corn, the mandate increased the demand for corn and farmers responded by growing more corn.

b. Why would you expect an increase in the quantity of corn produced to raise the opportunity cost of corn?

Increasing the quantity of corn produced results in a higher opportunity cost of corn because acreage less suited to growing corn is shifted away from other crops and into corn. As increasingly less suitable acreage is used, the opportunity cost of in terms of other crops forgone increases.

c. Why did the cost of producing corn increase in the rest of the world?The cost of producing corn in the rest of the world increased for two reasons. First in other parts of the world, droughts decreased the corn harvest and thereby increased the opportunity cost of the land that was being used to grow corn. Second the increased demand for corn from people who had previously been destitute increased the land devoted to growing corn, which also raised the opportunity cost of producing corn.

d. Is it possible that the increased quantity of corn produced, despite the higher cost of production, moves the United States closer to allocative efficiency?

It is possible that the increased quantity of corn has moved the United States closer to allocative efficiency. The marginal benefit from ethanol increased because of the higher price for gasoline, so the allocatively efficient quantity of ethanol increased. To increase the production of ethanol more corn had to be produced, so even with the higher opportunity cost, the United States might have moved closer to the allocatively efficient point of production.

22. Use the links on MyEconLab (Textbook Resources, Chapter 2, Weblinks) to obtain data on the tuition and other costs of enrolling in the MBA program at a school that interests you.

a. Draw a PPF that shows the tradeoff that you would face if you decided to enroll in the MBA program.

The PPF a student draws should be similar to Figure 2.19. The PPF should show the quantity of consumption goods and services on one axis and the quantity of education goods and services on the other axis and should be bowed out from the origin.

b. Do you think your marginal benefit of an MBA exceeds your marginal cost?

Whether a particular student believes that the marginal benefit of an MBA exceeds his or her marginal cost depends on the marginal cost of the MBA program the student selected and the student’s marginal benefit, such as expected future jobs, of an MBA degree from that program.

c. Based on your answer to b, do you plan to enroll in an MBA program? Is your answer to this question consistent with using your time to achieve your self-interest?

The student should plan to enroll in an MBA program if the marginal benefit (to the student) exceeds the marginal cost (to the student). This decision will be made on the basis of furthering the student’s self interest.

A n s w e r s t o t h e P r o b l e m s a n d A p p l i c a t i o n s1. William Gregg owned a mill in South Carolina. In December 1862, he

placed a notice in the Edgehill Advertiser announcing his willingness to exchange cloth for food and other items. Here is an extract:1 yard of cloth for 1 pound of bacon2 yards of cloth for 1 pound of butter4 yards of cloth for 1 pound of wool8 yards of cloth for 1 bushel of salt

a. What is the relative price of butter in terms of wool?1 pound of butter exchanged for 2 yards of cloth and 4 yards of cloth exchanged for 1 pound of wool. Hence 1 pound of butter exchanged for 2 yards of cloth and 2 yards of cloth exchanged for 1/2 pound of wool. So the relative price of butter in terms of wool was 1/2 pound of wool per pound of butter.

b. If the money price of bacon was 20¢ a pound, what do you predict was the money price of butter?

1 pound of bacon exchanged for 1 yard of cloth and 2 yards of cloth exchanged for 1 pound of butter. Hence it took 2 pounds of bacon to exchange for 1 pound of butter. As a result, if the money price of a pound of bacon was 20¢ the money price of 1 pound of butter was 40¢.

c. If the money price of bacon was 20¢ a pound and the money price of salt was $2.00 a bushel, do you think anyone would accept Mr. Gregg’s offer of cloth for salt?

If the money price of bacon is 20¢ a pound, Mr. Gregg’s offer to exchange 1 pound of bacon for 1 yard of cloth means that anyone could obtain 1 yard of cloth for a money price of 20¢. Mr. Gregg’s further offer to exchange 8 yards of cloth for 1 bushel of salt means that anyone could acquire 1 bushel of salt for $1.60, the price of 8 yards of cloth. If the money price of salt is $2.00 a bushel, many people would accept Mr. Gregg’s offer of cloth for salt because it enables them to obtain salt at a money price of only $1.60 a bushel.

2. The price of food increased during the past year.a. Explain why the law of demand applies to food just as it does to all other

goods and services.The law of demand applies to food because there is both a substitution and an income effect that reinforce each other. When the price rises, people substitute to different foods. For instance, some might substitute home cooked meals for dining at a restaurant. And when the price rises, there is a negative income effect, so people they buy less of food overall and less food with the rising price. On both counts, the higher price of food decreases the quantity of food demanded.

b. Explain how the substitution effect influences food purchases and provide some examples of substitutions that people might make when the price of food rises and other things remain the same.

People substitute in two ways: They substitute cheaper foods for more expensive foods and also substitute diets for food.

c. Explain how the income effect influences food purchases and provide some examples of the income effect that might occur when the price of food rises and other things remain the same.

Food is a normal good so a rise in the price, which decreases people’s real incomes, decreases the quantity of food demanded. In the United States, restaurants suffer as the negative income effect from a higher price of food leads people to cut back their trips to restaurants. In poor countries, people literally eat less when the price of food rises and in extremely poor countries starvation increases.

3. Place the following goods and services into pairs of likely substitutes and into pairs of likely complements. (You may use an item in more than one pair.) The goods and services are:

coal, oil, natural gas, wheat, corn, rye, pasta, pizza, sausage, skateboard, roller blades, video game, laptop, iPod, cell phone, text message, email, phone call, voice mail

Substitutes include: coal and oil; coal and natural gas; oil and natural gas; wheat and corn; wheat and rye; corn and rye; pasta and pizza; pasta and sausage; pizza and sausage (they type of sausage that cannot be used as a topping on pizza); skateboard and roller blades; skateboard and video game; roller blades and video game; text message and email; text message and phone call; and, email and phone call.

Complements include: pizza and sausage (the type of sausage that can be used as a topping on pizza); skateboard and iPod; roller blades and iPod; video game (the type played on a computer) and laptop; cell phone and text message; cell phone and phone call; cell phone and voice mail; and, phone call and voice mail.

4. During 2008, the average income in China increased by 10 percent. Compared to 2007, how do you expect the following would change:

a. The demand for beef? Explain your answer.Beef is a normal good. The increase in income increases the demand for beef.

b. The demand for rice? Explain your answer.Rice is probably an inferior good. The increase in income decreases the demand for rice.

5. In January 2007, the price of gasoline was $2.38 a gallon. By May 2008, the price had increased to $3.84 a gallon. Assume that there were no changes in average income, population, or any other influence on buying plans. How would you expect the rise in the price of gasoline to affect

a. The demand for gasoline? Explain your answer.The rise in the price of gasoline does not change the demand for gasoline. The demand for gasoline changes only when some other relevant factor other than the price of the good changes.

b. The quantity of gasoline demanded? Explain your answer.The rise in the price of gasoline decreases the quantity of gasoline demanded. A rise in the price of a good or service decreases the quantity of that good or service demanded.

6. In 2008, the price of corn increased by 35 percent and some cotton farmers in Texas stopped growing cotton and started to grow corn.

a. Does this fact illustrate the law of demand or the law of supply? Explain your answer.

This fact illustrates the law of supply: the higher price of corn lead some farmers to increase the quantity of corn they grow.

b. Why would a cotton farmer grow corn?A cotton farmer would switch to corn because the profit from growing corn exceeds that from growing cotton. Cotton and corn are substitutes in production. A farmer making his or her decisions based on his or her self interest will respond to a rise in the price of corn by producing corn rather than cotton.

7. American to cut flights, charge for luggageAmerican Airlines announced yesterday that it will begin charging passengers $15 for their first piece of checked luggage, in addition to raising other fees and cutting domestic flights as it grapples with record-high fuel prices.

Boston Herald, May 22, 2008a. How does this news clip illustrate a change in supply? Explain your

answer.Fuel prices are a cost of a factor of production. As the cost rises, the supply decreases. American Airlines is decreasing the supply of its flights by cutting domestic flights.

b. What is the influence on supply identified in the news clip? Explain your answer.

The influence is the cost of a factor of production, in particular, the cost of fuel.

c. Explain how supply changes.The increase in the cost of the factor of production decreases the supply and shifts the supply curve leftward.

8. Oil soars to new record over $135The price of oil hit a record high above $135 a barrel on Thursday—more than twice what it cost a year ago ... OPEC has so far blamed price rises on speculators and says there is no shortage of oil.

BBC News 22 May 2008a. Explain how the price of oil can rise even though there is no shortage of

oil.There is a shortage of oil if the price of oil is less than the equilibrium price. The equilibrium price of oil rises if the demand for oil increases and/or the supply decreases. So in these cases if the price of oil equals the equilibrium price, the price of oil rises and there is no shortage.

b. If a shortage of oil does occur, what does that imply about price adjustments and the role of price as a regulator in the market for oil?

If a persisting shortage of oil occurs, the implication is that price adjustments are slow so that the price is not an efficient regulator in the market for oil.

c. If OPEC is correct, what factors might have changed demand and/or supply and shifted the demand curve and/or the supply curve to cause the price to rise?

If OPEC is correct, speculators affect the current price of oil because they expect the price will be higher in the future. In this case the current demand

for oil increases (as speculators buy oil to store for the future when the price is expected to be higher) and the current supply decreases (as speculators who already own oil store it to wait for the higher price expected in the future). The increase in current demand combined with the decrease in current supply raises the current price of oil.

9. “As more people buy computers, the demand for Internet service increases and the price of Internet service decreases. The fall in the price of Internet service decreases the supply of Internet service.” Is this statement true or false? Explain.

The statement is false for several reasons. First, if the demand for Internet services increases and nothing else changes, the price of Internet service will rise not fall. Second, if the price of Internet services falls, the supply of Internet services does not change. Rather, there is a decrease in the quantity supplied, that is, a movement along the supply curve rather than a shift of the supply curve.

10. The following events occur one at a time:(i) The price of crude oil rises.(ii) The price of a car rises.(iii) All speed limits on highways are abolished.(iv) Robots cut car production costs.Which of these events will increase or decrease (state which occurs)

a. The demand for gasoline?(ii) and (iii) and (iv) change the demand for gasoline.The demand for gasoline will change if the price of a car rises, all speed limits on highways are abolished, or robot production cuts the cost of producing a car. If the price of a car rises, the quantity of cars bought decrease and the demand for gasoline decreases. If all speed limits on highways are abolished, people will drive faster and use more gasoline. The demand for gasoline increases. If robot production plants lower the cost of producing a car, the supply of cars will increase. With no change in the demand for cars, the price of a car will fall and more cars will be bought. The demand for gasoline increases.

b. The supply of gasoline?(i) changes the supply of gasoline.The supply of gasoline will change if the price of crude oil (a factor of production used in the production of gasoline) changes. If the price of crude oil rises, the cost of producing gasoline rises and the supply of gasoline decreases.

c. The quantity of gasoline demanded?(i) changes the quantity of gasoline demanded.If the price of crude oil rises, the cost of producing gasoline rises and the supply of gasoline decreases. The demand for gasoline does not change. The price of gasoline rises and there is a movement up the demand curve for gasoline. The quantity of gasoline demanded decreases.

d. The quantity of gasoline supplied?(ii) and (iii) and (iv) change the quantity of gasoline supplied.If the price of a car rises, the quantity of cars bought decrease so the demand for gasoline decreases. The supply of gasoline does not change. The price of gasoline falls and there is a movement down the supply curve of gasoline. The quantity of gasoline supplied decreases.

If all speed limits on highways are abolished, people will drive faster and use more gasoline. The demand for gasoline increases. The supply of gasoline does not change, so the price of gasoline rises and there is a movement up along the supply curve. The quantity of gasoline supplied increases.If robot production plants lower the cost of producing a car, the supply of cars will increase. With no change in the demand for cars, the price of a car will fall and more cars will be bought. The demand for gasoline increases. The supply of gasoline does not change, so the price of gasoline rises and the quantity of gasoline supplied increases.

11. The demand and supply schedules for gum are given in the table.

a. Draw a graph of the gum market, label the axes and the curves, and mark in the equilibrium price and quantity.

Figure 3.1, on the next page, shows the demand and supply curves. The equilibrium price is 50 cents a pack, and the equilibrium quantity is 120 million packs a week. The price of a pack adjusts until the quantity demanded equals the quantity supplied. At 50 cents a pack, the quantity demanded is 120 million packs a week and the quantity supplied is 120 million packs a week.

b. Suppose that the price of gum is 70¢ a pack. Describe the situation in the gum market and explain how the price adjusts.

At 70 cents a pack, there is a surplus of gum and the price falls. At 70 cents a pack, the quantity demanded is 80 million packs a week and the quantity supplied is 160 million packs a week. There is a surplus of 80 million packs a week. The price falls until market equilibrium is restored at a price of 50 cents a pack.

c. Suppose that the price of gum is 30¢ a pack. Describe the situation in the gum market and explain how the price adjusts.

At 30 cents a pack, there is a shortage of gum and the price rises. At 30 cents a pack, the quantity demanded is 160 million packs a week and the quantity supplied is 80 million packs a week. There is a shortage of 80 million packs a week. The price rises until market equilibrium is restored at a price of 50 cents a pack.

PriceQuantity demande

d

Quantitysupplied

(cents per pack)

(millions of packs a week)

20 180 60 40 140 100 60 100 140 80 60 180100 20 220

d. A fire destroys some factories that produce gum and the quantity of gum supplied decreases by 40 million packs a week at each price. Explain what happens in the market for gum and illustrate the changes on your graph.

As the number of gum-producing factories decreases, the supply of gum decreases. There is a new supply schedule and, in Figure 3.2, the supply curves shifts leftward by 40 million packs at each price to the new supply curve S1. After the fire, the quantity supplied at 50 cents is now only 80 million packs, and there is a shortage of gum. The price rises to 60 cents a pack, at which the new quantity supplied equals the quantity demanded (100 million packs a week). So the new equilibrium price is 60 cents and the new equilibrium quantity is 100 million packs a week.

e. If at the time the fire occurs in d, there is an increase in the teenage population, which increases the quantity of gum demanded by 40 million packs a week at each price. What are the new equilibrium price and quantity of gum? Illustrate these changes in your graph.

The new price is 70 cents a pack, and the quantity is 120 million packs a week. The demand for gum increases and the demand curve shifts rightward by 40 million packs at each price. Supply decreases by 40 millions packs a week and the supply curve shifts leftward by 40 million packs at each price. These changes are shown in Figure 3.3 by the shift of the demand curve from D to D1 and the shift of the supply curve from S to S1. At any price below 70 cents a pack there is a shortage of gum. The price of gum rises until the shortage is eliminated.

12. Eurostar boosted by Da Vinci CodeEurostar, the train service linking London to Paris. . . , said on Wednesday first-half sales rose 6 per cent, boosted by devotees of the blockbuster Da Vinci movie.

CNN, July 26, 2006a. Explain how Da Vinci Code fans helped to raise Eurostar’s sales.

The Da Vinci Code was placed in France and the United Kingdom and the movie was filmed in France and in the United Kingdom. Many fans celebrated the movie and book by holidaying in France and the United Kingdom in order to trace the path of the protagonists. These tourists increased the demand for train travel between London and Paris.

b. CNN commented on the “fierce competition from budget airlines.” Explain the effect of this competition on Eurostar’s sales.

Travel by budget airlines is a substitute for travel by Eurostar. Fierce competition from budget airlines means that the budget airlines have lowered the price of their fares. This fall in the price of a substitute decreases the demand for travel by Eurostar. Taken by itself, this factor decreased Eurostar’s sales.

c. What markets in Paris do you think these fans influenced? Explain the influence on three markets.

The Da Vinci Code movie fans were tourists in Paris and so increased the demand for tourist activities. The increase in tourists in Paris increased the demand for restaurant meals, increased the demand for lodging, and increased the demand for transportation within Paris.

13. Of gambling, grannies and good senseNevada has the fastest growing elderly population of any state. . . . Las Vegas has . . . plenty of jobs for the over 50s.

The Economist, July 26, 2006

Explain how grannies have influenced thea. Demand side of some Las Vegas markets.

On the average, elderly people require more health care services than younger people. So the influx of older people into Las Vegas increased the demand for medical services and pharmaceutical drugs and services. Older people also eat out more often and do less yard work. So the demand for restaurant meals and yard care maintenance increased.

b. Supply side of other Las Vegas markets.Older but not-yet retired people work, so the increase in “grannies” increased the supply of labor.

14. Use the link on MyEconLab (Textbook Resources, Chapter 3, Web Links) to obtain data on the prices and quantities of bananas in 1985 and 2002.

a. Make a graph to illustrate the market for bananas in 1985 and 2002.Between 1985 and 2002, according to the FAO in The World Banana Economy, 1985-2002 the quantity of dessert bananas increased from 40,088,000 MT to 69,832,000 MT while the real U.S. retail price fell from $1.13 per kg to $0.95 per kg. The students’ graphs should be similar to Figurer 3.4 by showing the demand for and supply of bananas intersecting at their equilibrium price and quantity of bananas in 1985 and 2002.

b. On the graph, show the changes in demand and supply and the changes in the quantity demanded and the quantity supplied that are consistent with the price and quantity data.

Likely both the demand and supply increased, but the increase in supply was larger than the increase in demand.

c. Why do you think the demand for and supply of bananas changed?Most likely demand increased because bananas are a normal good and income generally increased over this period. The supply of bananas increased for two reasons. First, more acreage was cultivated, particularly in Ecuador. Second, significant technological advances have occurred in transporting bananas (better refrigeration) and in ripening bananas (the use of ethylene to trigger the ripening process).

15. Use the link on MyEconLab (Textbook Resources, Chapter 3, Web Links) to obtain data on the price of oil since 2000.

a. Describe how the price of oil changed.Through at least the summer of 2008, the price of oil has generally risen since 2000.

b. Use a demand-supply graph to explain what happens to the price when supply increases or decreases and demand is unchanged.

When supply increases, the supply curve shifts rightward. The price falls. When supply decreases, the supply curve shifts leftward. The price rises.

c. What do you predict would happen to the price of oil if a new drilling technology permitted deeper ocean sources to be used?

If new drilling technology is developed, the supply of oil would increase and the supply curve would shift rightward. The price of oil would fall.

d. What do you predict would happen to the price of oil if a clean and safe nuclear technology were developed?

Energy produced using nuclear power is a substitute for energy produced using oil. If clean and safe nuclear technology is developed, the demand for oil would decrease and the demand curve would shift leftward. The price of oil would fall.

e. How does a higher price of oil influence the market for ethanol?Alternative fuels, such as ethanol, are a substitute for oil. A higher price of oil increases the demand for ethanol (refiners will produce more ethanol blended gasoline). The increase in demand for ethanol raises the price of ethanol and increases the quantity of ethanol.

f. How does an increase in the supply of ethanol influence the market for oil?

Alternative fuels, such as ethanol, are a substitute for oil. An increase in the supply of ethanol lowers the price of ethanol. As a result more drivers use ethanol blended fuels so the demand for oil decreases. The price of oil falls and the quantity decreases.

16. What features of the world market for crude oil make it a competitive market?

The world oil market is a competitive because there are a large number of suppliers and a large number of buyers. There are so many sellers and so many buyers that no individual seller or individual buyer can control the price of oil.

17. The money price of a textbook is $90 and the money price of the Wii game Super Mario Galaxy is $45.

a. What is the opportunity cost of a textbook in terms of the Wii game?A textbook costs $90 and a Wii game costs $45. Purchasing 1 textbook forces the buyer to forego 2 Wii games. So the opportunity cost of a textbook in terms of Wii games is 2 Wii games per textbook.

b. What is the relative price of the Wii game in terms of textbooks?The relative price of a Wii game in terms of textbooks ($45 per Wii)/($90 per textbook), which is 1/2 of a textbook per Wii game.

18. The price of gasoline has increased during the past year.a. Explain why the law of demand applies to gasoline just as it does to all

other goods and services.When the price of gasoline rises, people decrease the quantity of gasoline they demand. Both the substitution effect and the income effect lead consumers to decrease the quantity of gasoline demanded.

b. Explain how the substitution effect influences gasoline purchases and provide some examples of substitutions that people might make when the price of gasoline rises and other things remain the same.

When the price of gasoline rises, people substitute other goods and services for gasoline. For instance, people substitute public transport (such as buses), carpools, motorcycles, walking, and bicycles for driving alone in a car to work.

c. Explain how the income effect influences gasoline purchases and provide some examples of the income effects that might occur when the price of gasoline rises and other things remain the same.

When the price of gasoline rises, people’s real incomes fall. People respond by decreasing their demand for normal goods, such as gasoline. In the gasoline market, some people trade in large, fuel guzzling cars because they can no longer afford to fuel the large vehicle. Others will not purchase a car or truck because they are not able to afford the gasoline necessary to use it.

19. Classify the following pairs of goods and services as substitutes, complements, substitutes in production, or complements in production.

a. Bottled water and health club membershipsBottled water and health club memberships are complements because people in health clubs drink a lot of bottled water.

b. French fries and baked potatoesFor a consumer, French fries and baked potatoes are substitutes. For a restaurant that produces both French fries and baked potatoes, they are substitutes in production.

c. Leather purses and leather shoesLeather purses and leather shoes are substitutes in production.

d. SUVs and pickup trucksFor a consumer, SUVs and pickup trucks are substitutes. For an auto company that produces both on the same assembly line, they are substitutes in production.

e. Diet coke and regular cokeFor a consumer, Diet coke and regular coke are substitutes. For a soda company that produces both on the same assembly line, they are substitutes in production.

f. Low-fat milk and creamLow-fat milk and cream are complements in production.

20. Think about the demand for the three popular game consoles: XBox, PS3, and Wii. What is the effect on the demand for XBox games and the quantity of XBox games demanded if, other things remaining the same:

a. The price of an XBox falls?An XBox and an XBox game are complements. When the price of an XBox falls, consumers respond by increasing the quantity of XBoxes demanded so the equilibrium quantity of XBoxes increases. Consumers increase their demand for XBox games because an XBox console is useless without XBox games.

b. The prices of a PS3 and a Wii fall?A PS3 and a Wii are substitutes for an XBox. When these game consoles falls in price, the demand for XBox consoles decreases and so the equilibrium quantity of XBoxes decreases. Consumers decrease their demand for XBox games because an XBox game is useless without an XBox console.

c. The number of people writing and producing XBox games increases?The increase in the number of people writing XBox games increases the supply of XBox games. The demand for XBox games does not change but the increase in the supply lowers the price of an XBox game. The fall in the price of XBox games increases the quantity of XBoxes demanded.

d. Consumers’ incomes increase?XBox games are surely a normal good. So an increase in consumers’ incomes increases the demand for XBox games.

e. Programmers who write code for XBox games become more costly to hire?

The increase in cost of programmers decreases the supply of XBox games. When the supply of a good or service decreases, the price of that good or service rises. XBox games are not an exception, so the price of an XBox game rises. The rise in the price of an XBox game decreases the quantity of XBox games demanded.

f. The price of an XBox game is expected to fall?When the price of an XBox game is expected to fall, the (current) demand for XBox games decreases.

g. A new game console comes onto the market, which is a close substitute for XBox.

The new game console decreases the demand for Xbox consoles. As a result, the equilibrium quantity of XBox consoles decreases. Consumers decrease their demand for Xbox games because an XBox game is useless without an XBox console.

21. In 2008, as the prices of homes fell across the United States, the number of homes offered for sale decreased.

a. Does this fact illustrate the law of demand or the law of supply? Explain your answer.

This fact illustrates the law of supply: As the price falls, the quantity supplied decreases.

b. Why would home owners hold off trying to sell?Home owners delay selling their homes because they believe the price they would receive is too low and the price they will receive in the future will be higher.

22. G.M. Cuts Production for QuarterGeneral Motors cut its fourth-quarter production schedule by 10 percent on Tuesday as a tightening credit market caused sales at the Ford Motor Company, Chrysler and even Toyota to decline in August. ... Bob Carter, group vice president for Toyota Motor Sales USA, said ... dealerships were still seeing fewer potential customers browsing the lots.

The New York Times, September 5, 2007

Explain whether this news clip illustratesa. A change in supply

The news clip does not illustrate a change in supply. None of the factors that change supply are mentioned in the story.

b. A change in the quantity suppliedThe news clip illustrates a change in the quantity supplied. G.M. faces a lower price for its vehicles and responded to that by decreasing the quantity of vehicles it produces.

c. A change in demandThe news clip illustrates a change in demand. In particular the tightening credit market decreases the demand for big ticket items, such as automobiles.

d. A change in the quantity demandedThe news clip does not illustrate a change in the quantity demanded. Consumers are reported as responding to the credit market not to a change in the price of vehicles.

23. Figure 3.5 illustrates the market for pizza.

a. Label the curves. Which curve shows the willingness to pay for a pizza?

The demand curve is the downward sloping curve and the supply curve is the upward sloping curve. The demand curve shows the willingness to pay for a pizza.

b. If the price of a pizza is $16, is there a shortage or a surplus and does the price rise or fall?

If the price of a pizza is $16, there is a surplus of pizza; the quantity supplied of pizzas exceeds the quantity demanded. The surplus forces the price lower to the equilibrium price of $14 a pizza.

c. Sellers want to receive the highest possible price, so why would they be willing to accept less than $16 a pizza?

Sellers are willing to accept less than $16 because if they charge $16 the surplus means that some sellers have unsold pizzas. From their perspective it is better to have a lower price for the pizza and sell the (decreased) quantity they produce than to keep the price at $16 and be left with unsold pizza.

d. If the price of a pizza is $12, is there a shortage or a surplus and does the price rise or fall?

If the price of a pizza is $12, there is a shortage of pizza; the quantity demanded of pizzas exceeds the quantity supplied. The shortage forces the price higher to the equilibrium price of $14 a pizza.

e. Buyers want to pay the lowest possible price, so why would they be willing to pay more than $12 for a pizza?

If the price of a pizza is $12 the shortage means that not all buyers can buy a pizza. From their perspective they would rather pay more than $12 and be able to purchase a pizza a pizza than to keep the price at $12 and leave them without a pizza.

24. Plenty of “For Sale” Signs but Actual Sales LaggingLike spring flowers, the “For Sale” signs are sprouting in front yards all over the country. But anxious sellers are facing the most brutal environment in decades, with a slumping economy, falling home prices, and rising mortgage fore closures.

The New York Times, May 26, 2008a. Describe the changes in demand and supply in the market for homes in

the United States.The supply of homes for sale seasonally increases in the spring. In the spring of 2008, however, the demand for homes decreased because the slumping

economy meant that consumers’ incomes were falling and the rising mortgage foreclosures meant that credit conditions were becoming adverse. As a result of the increase in supply and decrease in demand the prices of homes fell.

b. Is there a surplus of homes?The equilibrium price of a home falls. If the market price falls in line with the equilibrium price there is not a surplus of homes.

c. What does the information in the news clip imply about price adjustments and the role of price as a regulator in the market for homes?

The information in the news item suggests that there are more unsold homes than usual. If this interpretation of the story is correct and there is a larger inventory of unsold homes that normal, the market price might be sluggish in adjustment and be greater than the equilibrium price. In this case the price is not a totally efficient regulator in the market for homes.

25. ‘Popcorn Movie’ Experience Gets Pricier... cinemas are raising ... prices. … Demand for field corn, used for animal feed, ... corn syrup and ... ethanol, has caused its price to explode. That’s caused some farmers to shift from popcorn to easier-to-grow field corn, cutting supply and pushing its price higher, too....

USA Today, May 24, 2008Explain and illustrate graphically the events described in the news clip in the markets for

a. Popcorn.As illustrated in Figure 3.6, the farmers’ actions decrease the supply of popcorn and the supply curve of popcorn shifts leftward. The demand curve does not shift. The equilibrium price of popcorn rises and the quantity decreases.

b. Viewing movies in the theater.In the market for viewing movies in the theater, popcorn and viewing movies are complements. The increase in the price of popcorn decreases the demand for attending movies in the theater. As a result, Figure 3.7 shows the demand curve shifting leftward. The equilibrium price of attending a movie in the theater falls and the equilibrium quantity decreases.

26. The table sets out the demand and supply schedules for potato chips.

a. Draw a graph of the potato chip market and mark in the equilibrium price and quantity.

Figure 3.8 draws the supply and demand curves for this market. The equilibrium price is 65¢ a bag, and the equilibrium quantity is 145 million bags a week.

b. Describe the situation in the market for chips and explain how the price adjusts if chips are 60¢ a bag.

At 60¢ a bag, there is a shortage of potato chips and the price rises. At 60¢ a bag, the quantity demanded is 150 million bags a week and the quantity supplied is 140 million bags a week. The difference is a shortage of 10 million bags a week. The price rises until market equilibrium is restored—65¢ a bag and 145 million bags a week.

PriceQuantity demande

d

Quantitysupplied

(cents per bag)

(millions of bags a week)

50 160 130 60 150 140 70 140 150 80 130 160 90 120 170100 110 180

c. If a new dip increases the quantity of potato chips that people want to buy by 30 million bags per week at each price, how does the demand and/or supply of chips change?

As the new dip comes onto the market, the demand for potato chips increases and the demand curve shifts rightward. Supply does not change.

d. If a new dip has the effect described in c, how does the price and quantity of chips change?

Demand increases by 30 million bags a week. That is, the quantity demanded at each price increases by 30 million bags. The quantity demanded at 65¢ is now 175 million bags a week of potato chips. The price rises to 80¢ a bag, at which the quantity supplied equals the quantity demanded (160 million bags a week). Hence the new equilibrium price is 80¢ per bag and the new equilibrium quantity is 160 million bags.

e. If a virus destroys potato crops and the quantity of potato chips produced decreases by 40 million bags a week at each price, how does the supply of chips change?

The supply of potato chips decreases, and the supply curve shifts leftward. The quantity supplied at each price decreases by 40 million bags.

f. If the virus that destroys the potato crops in d hits just as the new dip in c comes onto the market, how does the price and quantity of chips change?

The result by itself of the new dip entering the market is a price of 80¢ a bag and a quantity of 160 million bags. But now with the virus affecting the market, at this price there is a shortage of potato chips. The price of potato chips rises until the shortage is eliminated. The new equilibrium price is 100¢ a bag, and the new equilibrium quantity is 140 million bags a week

27. Sony’s Blu-Ray Wins High-Definition WarToshiba Corp. yesterday raised the white flag in the war over the next-generation home movie format, announcing the end of its HD DVD business in a victory for Sony Corp.’s Blu-ray technology. The move could finally jump-start a high-definition home DVD market that has been hamstrung as consumers waited on the sidelines for the battle to play out in a fight reminiscent of the VHS-Betamax videotape war of the 1980s.

The Washington Times, February 20, 2008

How would you expect the end of Toshiba’s HD DVD format to influencea. The price of a used Toshiba player on eBay? Would the outcome that you

predict result from a change in demand or a change in supply or both, and in which directions?

The price of a used-Toshiba player falls. The price falls because the demand for these players decreases as potential buyers switch to Blu-ray players. The price also falls because the supply of these players increases as current owners move to discard their now semi-obsolete players.

b. The price of a Blu-ray player?The price of a Blu-ray player rises as people in the market for high definition DVD players now demand only Blu-ray players.

c. The demand for Blu-ray format movies?The demand for Blu-ray format movies increases because the quantity of Blu-ray players increases.

d. The supply of Blu-ray format movies?In the short run there is no change in the supply of Blu-ray movies, just a movement along the supply curve. But in the longer run movie studios that had previously been supporting only the Toshiba format will switch to the Blu-ray format and at that time the supply of Blu-ray movies will increase.

e. The price of Blu-ray format movies?In the short run, the price of Blu-ray format movies increases as a result of the increase in demand. In the longer run the effect on the price is ambiguous because the longer-run increase in supply lowers the price and thereby counters the initial effect of the increase in demand.

f. The quantity of Blu-ray format movies?The quantity of Blu-ray movies increases in the short run and even more so in the longer run.

28. After you have studied Reading Between the Lines on pp. 76–77, answer the following questions:

a. How high did the retail price of gasoline go in April 2008?The price rose to as high as $3.51 a gallon.

b. What substitutions did drivers make to decrease the quantity of gasoline demanded?

Drivers decreased the quantity of gasoline they demanded by slowing when going downhill and thereby substituting more time spent on the trip for less gasoline. They also substituted alternative means of transportation, including hybrid vehicles, the bus, a bicycle, and even a skateboard.

c. Why would the switch to summer-grade fuel and the seasonal increase in travel normally raises the price of gasoline in the spring?

Summer-grade fuel is more costly to blend and so it decreases the supply of gasoline. The seasonal increase in travel increases the demand for gasoline. Both changes—the decrease in supply and the increase in demand—raise the price of gasoline.

d. What were the two main factors that influenced the demand for gasoline in 2008 and how did they change demand?

The first factor was an increase in income. Higher incomes increased the demand for gasoline. But the increase in incomes was small and so the increase in demand also was small. The second factor was the gradual move toward hybrids and increased use of ethanol. These decreased the demand for gasoline. But these effects were also small. The two main factors offset each other so, on net, the demand for gasoline did not change.

e. What was the main influence on the supply of gasoline during 2007 and 2008 and how did supply change?

The main influence on the supply of gasoline was the soaring price of crude oil. This higher cost decreased the supply of gasoline.

f. How did the combination of the factors you have noted in d and e influence the price and quantity of gasoline?

The supply decreased while the demand did not change. Hence the supply curve shifted leftward and the demand curve did not shift. As a result, the equilibrium price of gasoline rose and the equilibrium quantity decreased.

g. Was the change in quantity a change in the quantity demanded or a change in the quantity supplied?

The supply of gasoline decreased while the demand did not change. As a result there was a decrease in the quantity of gasoline demanded.

A d d i t i o n a l P r o b l e m s1. What is the effect on the price of hotdogs and the quantity of hotdogs sold

ifa. The price of a hamburger rises?b. The price of a hotdog bun rises?c. The supply of hotdog sausages increases?d. Consumers’ incomes increase if hot dogs are a normal good?e. The wage rate of a hotdog seller increases?f. If the wage rate of the hotdog seller rises and at the same time prices of

ketchup, mustard, and relish fall?

2. Suppose that one of the following events occurs:(i) The price of wool rises.(ii) The price of sweaters falls.(iii) A close substitute for wool is invented.(iv) A new high-speed loom is invented.

Which of the above events increases or decreases (state which)a. The demand for wool?b. The supply of wool?c. The quantity of wool demanded?d. The quantity of wool supplied?

3. The figure illustrates the market for bread.

a. Label the curves in the figure.b. What are the equilibrium price of

bread and the equilibrium quantity of bread?