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Microeconomics: Principles and Applications

Robert E. Hall, Marc Liberman

Chapter 11

Monopolistic Competition and Oligopoly - all with Video Answers

Educators

AM

Chapter Questions

02:08

Problem 1

Draw the relevant curves to show a monopolistic competitor suffering a loss in the short run. What will this firm do in the long run if the situation does not improve? (Assume its $A T C$ and $M C$ curves don't change in the long run. How would this action affect other firms in this market?

Jesse Leija
Jesse Leija
Numerade Educator
04:54

Problem 2

The owner of an optometry practice, in a city with more than a hundred other such practices, has the following demand and cost schedules for eye exams:
a. Fill in the columns for total revenue, marginal revenue, and marginal cost. (Remember to put $M R$ and $M C$ between output levels.)
b. Briefly explain why an optometry practice (like this one) might face a downward-sloping demand curve, even if it is one out of more than
a hundred. (Hint: What might make this market monopolistically competitive rather than perfectly competitive?)
c. Use the data you filled in for the marginal revenue and marginal cost columns to find the profitmaximizing price and the profit-maximizing number of eye exams per week for this practice.

Jesse Leija
Jesse Leija
Numerade Educator
01:43

Problem 3

Suppose that the cost data in problem 2 are for the short run, and that the owner of the practice suddenly realizes that she forgot to include her only fixed cost:
her license fee of $\$ 2,600$ per year (which is $\$ 50$ per week). Should the practice shut down in the short run? Why or why not?

Jesse Leija
Jesse Leija
Numerade Educator
07:26

Problem 4

Tino owns a taco stand in Houston, Texas, where there are dozens of other taco stands. He faces the following demand and cost schedules for his taco plates (two tacos and a side of refried beans):
a. Fill in the columns for total revenue, marginal revenue, and marginal cost and use the table to find the profit-maximizing price and the profitmaximizing number of taco plates per week for Tino's Taco Stand. (Remember to put $M R$ and MC between output levels.)
b. Redo the table to show what will happen in the short run if Tino spends $\$ 100$ on an advertising campaign that increases the quantity demanded at each output level by 20 percent. What will happen to his profit-maximizing price and profitmaximizing number of taco plates per week? Do you expect this outcome to persist? Explain.

Jesse Leija
Jesse Leija
Numerade Educator
02:56

Problem 5

Assume that the plastics business is monopolistically competitive.
a. Draw a graph showing the long-run equilibrium situation for a typical firm in the industry. Clearly label the demand, $M R, M C,$ and $A T C$ curves.
b. One of the major inputs into plastics is oil. Draw a new graph illustrating the short-run position of a plastics company after an increase in oil prices. Again, show all relevant curves.
c. If oil prices remain at the new, higher level, what will happen to get firms in the plastics industry back to a long-run equilibrium? (Assume the firm's $A T C$ and $M C$ curves don't change in the long run.

Jesse Leija
Jesse Leija
Numerade Educator
03:20

Problem 6

Draw a diagram, including demand, marginal revenue, marginal cost, and any other curves necessary, to illustrate each of the following two situations for a monopolistic competitor:
a. The firm is suffering a loss, and it should shut down in the short run.
b. The firm is suffering a loss, but it should stay open in the short run.

Jesse Leija
Jesse Leija
Numerade Educator
02:51

Problem 7

Suppose there are five firms in a market, with the following market shares:
Firm A: $30 \%$ Firm B: $25 \%$ Firm $\mathrm{C}: 20 \%$
Firm D: $15 \%$ Firm E: $10 \%$
a. What is the 4 -firm concentration ratio?
b. What is the 8 -firm concentration ratio?
c. What is the HHI?

Jesse Leija
Jesse Leija
Numerade Educator
01:54

Problem 8

Starting with the data in problem $7,$ suppose that Firm A manages to take 5 percentage points of market share away from Firm C.
a. What is the 4 -firm concentration ratio now?
b. What is the 8 -firm concentration ratio now?
c. What is the HHI now?
d. Comparing your answers with those in problem
$7,$ which measures have changed, and which have remained the same?

Jesse Leija
Jesse Leija
Numerade Educator
03:54

Problem 9

Suppose there are only four ice cream manufacturers in a market, with the following market shares:
Delicious Brand: $\quad 35 \%$
Better Ice Cream: $\quad 30 \%$
To Die For: $\quad 25 \%$
Sven and Mary's $10 \%$
Sven and Mary want to give up making ice cream and retire. According to the U.S. government's 2010 guidelines, which (if any) of the other three companies would be permitted to purchase Sven and Mary's company without inviting government opposition?

Jesse Leija
Jesse Leija
Numerade Educator
02:09

Problem 10

In September 2011 , the U.S. government announced that it would go to court to block AT\&T's planned acquisition of T-Mobile. At the time, the market shares of the four largest wireless carriers (which together had about $90 \%$ of the market) were roughly as follows:
Verizon $33 \%$
AT\&T $\quad 31 \%$
Sprint $16 \%$
T-Mobile $10 \%$
a. Ignoring the other small wireless firms not shown, what was the value of the HHI before the planned acquisition?
b. What would be the value of the HIHI be if the proposed acquisition were completed?
c. Was the U.S. government's opposition to the merger consistent with its 2010 guidelines? Explain briefly.

Jesse Leija
Jesse Leija
Numerade Educator
05:58

Problem 11

In a small Nevada town, Ptomaine Flats, there are only two restaurants, the Road Kill Café and, for Italian fare, Sal Monella's. Each restaurant has to decide whether to clean up its act or continue to ignore health code violations.

Each restaurant currently makes $\$ 7,000$ a year in profit. If they both tidy up a bit, they will attract more patrons but must bear the (substantial) cost of the cleanup; so they will both be left with a profit of $\$ 5,000 .$ However, if one cleans up and the other doesn't, the influx of diners to the cleaner joint will more than cover the costs of the scrubbing; the more hygienic place ends up with $\$ 12,000,$ and the grubbier establishment incurs a loss of $\$ 3,000$
a. Write out the payoff matrix for this game, clearly labeling strategies and payoffs to each player.
b. What is each player's dominant strategy?
c. What will be the outcome of the game? Explain your answer.
d. Suppose the two restaurants believe they will face the same decision repeatedly. How might the outcome differ? Why?
e. Assume that if one cleans up and one stays dirty, the cleaner restaurant makes only $\$ 6,000$ in profit. All other payoffs are the same as before. What will the outcome of the game be now without cooperation? With cooperation?

Jesse Leija
Jesse Leija
Numerade Educator
03:08

Problem 12

Assume that Nike and Adidas are the only sellers of athletic footwear in the United States. They are deciding how much to charge for similar shoes. The two choices are "High" (H) and " Outrageously High" (OH). Nike's payoffs are in the lower left of each cell in the payoff matrix below:
a. Do both companies have dominant strategies? If so, what are they?
b. What will be the outcome of the game?

Jesse Leija
Jesse Leija
Numerade Educator
01:54

Problem 13

[Requires Appendix] In Figure A.2, suppose that Bole is already cheating by selling 80 million pounds of bananas, while Bel Monte is sticking to its agreed allotment of 60 million, and earning profit of $\$ 15$ million.
a. If Bel Monte decides to cheat too and sell 80 million, what will be the new market price? IHint: Use the fact that the demand curve is linear.
b. What will be Bel Monte's profit now?
c. What will be Bole's profit now?

Jesse Leija
Jesse Leija
Numerade Educator
01:40

Problem 14

[Requires Appendix] In Figure A.2, suppose that both Bole and Bel Monte are each selling 80 million-in violation of the agreement. If one stays at 80 million, does the other have an incentive to increase sales by another 20 million? Explain briefly.

Jesse Leija
Jesse Leija
Numerade Educator
01:46

Problem 15

Suppose that the government has decided to tax all the firms in a monopolistically competitive industry by levying a fixed tax on each firm; that is, the amount of the tax is the same regardless of how much output the firm produces. In the short run, how would the tax affect the price, output level, and profit of a typical firm in that industry? What would be the effect in the long run?

Jesse Leija
Jesse Leija
Numerade Educator
02:25

Problem 16

Below, you will find the payoff matrix for a twoplayer game, where each player has three possible strategies: $A, B,$ and $C .$ The payoff for player 1 is listed in the lower left portion of each cell. Assume there is no cooperation among players.
a. Does either player have a dominant strategy? If so, which player or players, and what is the dominant strategy?
b. Can we predict the outcome of this game from the payoff matrix using the methods you've learned in the chapter? Why or why not?
c. Suppose that strategy $\mathrm{C}$ is no longer available to either player. Does either player have a dominant strategy now? Can you now predict the outcome of the game? Explain.

Jesse Leija
Jesse Leija
Numerade Educator
04:33

Problem 17

State whether each of the following is mathematically possible or impossible:
a. A market has a 4 -firm concentration ratio of $50 \%,$ and an HHI of 600
b. A market has a 4 -firm concentration ratio of $50 \%,$ and an HHI of 3,000
c. A market has a 4 -firm concentration ratio of $100 \%,$ and an HHI of 5,000

Jesse Leija
Jesse Leija
Numerade Educator