平狄克《微观经济学》课后答案 13-14

CHAPTER 13

GAME THEORY AND COMPETITIVE STRATEGY

Chapter 13 continues the discussion of competitive firms in the context of two-player games, with the first three sections covering all topics introduced in Chapter 12. If you did not present Section 12.5, you should do so after discussing Sections 13.1 and 13.2. Sections 13.4 through 13.8 introduce advanced topics. The presentation throughout the chapter focuses on the intuition behind each model or strategy. The exercises focus on relating Chapter 13 to Chapter 12 and on behavior in repeated games.

Two concepts pervade this chapter: rationality and equilibrium. Assuming the players are rational means that each player maximizes his or her own payoff whether it hurts or helps other players. Rationality underlies many of the equilibria in the chapter. Underlying all these models is the definition of a Nash equilibrium, which the students will find esoteric. When presenting each model, ask whether a unique Nash equilibrium exists. If there is more than one, discuss the conditions that will favor each equilibrium.

The analysis in the last five sections of the chapter is more demanding, but the examples are more detailed. Section 13.4 examines repeated games, and it will be important to discuss the role of rationality in the achievement of an equilibrium in both finite- and infinite-horizon games. Example 13.2 points out conditions that lead to stability in repeated games, while Example 13.3 presents an unstable case. Sections 13.5, 13.6, and 13.7 introduce strategy in the context of sequential games. To capture the students’ attention, discuss the phenomenal success of Wal-Mart in its attempt to preempt the entry of other discount stores in rural areas (see Example 13.4). First, define a strategic move; second, discuss the advantage of moving first; third, present Example 13.4; and fourth, continue with other forms of strategic behavior, including the use of new capacity and R&D to deter entry (see Examples 13.5 and 13.6). You may wish to reintroduce the case of bilateral monopoly during the discussion of strategic behavior in cooperative games, which concludes this chapter.

1. What is the difference between a cooperative and a noncooperative game? Give an example of each.

In a noncooperative game the players do not formally communicate in an effort to

coordinate their actions. They are aware of one another’s existence, but act

independently. The primary difference between a cooperative and a noncooperative

game is that a binding contract, i.e., an agreement between the parties to which both

parties must adhere, is possible in the former, but not in the latter. An example of a

cooperative game would be a formal cartel agreement, such as OPEC, or a joint venture.

An example of a noncooperative game would be a race in research and development to

obtain a patent.

2. What is a dominant strategy? Why is an equilibrium stable in dominant strategies?

A dominant strategy is one that is best no matter what action is taken by the other

party to the game. When both players have dominant strategies, the outcome is stable

because neither party has an incentive to change.

3. Explain the meaning of a Nash equilibrium. How does it differ from an equilibrium in dominant strategies?

A Nash equilibrium is an outcome where both players correctly believe that they are

doing the best they can, given the action of the other player. A game is in equilibrium if

neither player has an incentive to change his or her choice, unless there is a change by

the other player. The key feature that distinguishes a Nash equilibrium from an

equilibrium in dominant strategies is the dependence on the opponent’s behavior. An

equilibrium in dominant strategies results if each player has a best choice, regardless of

the other player’s choice. Every dominant strategy equilibrium is a Nash equilibrium

but the reverse does not hold.

4. How does a Nash equilibrium differ from a game’s maximin solution? In what situations is a maximin solution a more likely outcome than a Nash equilibrium?

A maximin strategy is one in which each player determines the worst outcome for each

of the opponent’s actions and chooses the option that maximizes the minimum gain that

can be earned. Unlike the Nash equilibrium, the maximin solution does not require

players to react to an opponent’s choice. If no dominant strategy exists (in which case

outcomes depend on the opponent’s behavior), players can reduce the uncertainty

inherent in relying on the opponent’s rationality by conse rvatively following a maximin

strategy. The maximin solution is more likely than the Nash solution in cases where

there is a higher probability of irrational (non-optimizing) behavior.

5. What is a “tit-for-tat” strategy? Why is it a rational strategy f or the infinitely repeated Prisoners’ Dilemma?

A player following a “tit-for-tat” strategy will cooperate as long as his or her opponent is

cooperating and will switch to a noncooperative strategy if their opponent switches

strategies. When the competitors assume that they will be repeating their interaction

in every future period, the long-term gains from cooperating will outweigh any

short-term gains from not cooperating. Because the “tit-for-tat” strategy encourages

cooperation in infinitely repeated games, it is rational.

6. Consider a game in which the Prisoners’ Dilemma is repeated 10 times, and both players are rational and fully informed. Is a tit-for-tat strategy optimal in this case? Under what conditions would such a strategy be optimal?

Since cooperation will unravel from the last period back to the first period, the

“tit-for-tat” strategy is not optimal when there is a finite number of periods and both

players anticipate the competitor’s response in every period. Given that there is no

response possible in the eleventh period for action in the tenth (and last) period,

cooperation breaks down in the last period. Then, knowing that there is no

cooperation in the last period, players should maximize their self-interest by not

cooperating in the second-to-last period. This unraveling occurs because both players

assume that the other player has considered all consequences in all periods. However,

if there is some doubt about whether the opponent has fully anticipated the

consequences of the “ti t-for-tat” strategy in the final period, the game will not unravel

and the “tit-for-tat” strategy can be optimal.

7. Suppose you and your competitor are playing the pricing game shown in Table 13.8. Both of you must announce your prices at the same time. Might you improve your outcome by promising your competitor that you will announce a high price?

If the game is to be played only a few times, there is little to gain. If you are Firm 1

and promise to announce a high price, Firm 2 will undercut you and you will end up

with a payoff of -50. However, next period you will undercut too, and both firms will

earn 10. If the game is played many times, there is a better chance that Firm 2 will

realize that if it matches your high price, the long-term payoff of 50 each period is better

than 100 at first and 10 thereafter.

8. What is meant by “first-mover advantage”? Give an example of a gaming situation with

a first-mover advantage.

A “first-mover” advantage can occur in a game where the first player to act r eceives the

highest payoff. The first-mover signals his or her choice to the opponent, and the

opponent must choose a response, given this signal. The first-mover goes on the

offensive and the second-mover responds defensively. In many recreational games,

from chess to football, the first-mover has an advantage. In many markets, the first

firm to introduce a product can set the standard for competitors to follow. In some

cases, the standard-setting power of the first mover becomes so pervasive in the market

that the brand name of the product becomes synonymous with the product, e.g.,

“Kleenex,” the name of Kleenex-brand facial tissue, is used by many consumers to refer

to facial tissue of any brand.

9. What is a “strategic move”? How can the developme nt of a certain kind of reputation be

a strategic move?

A strategic move involves a commitment to reduce one’s options. The strategic move

might not seem rational outside the context of the game in which it is played, but it is

rational given the anticipated response of the other player. Random responses to an

opponent’s action may not appear to be rational, but developing a reputation of being

unpredictable could lead to higher payoffs in the long run. Another example would be

making a promise to give a discount to all previous consumers if you give a discount to

one. Such a move makes the firm vulnerable, but the goal of such a strategic move is

to signal to rivals that you won’t be discounting price and hope that your rivals follow

suit.

10. Can the threat of a price war deter entry by potential competitors? What actions might a firm take to make this threat credible?

Both the incumbent and the potential entrant know that a price war will leave their

firms worse off. Normally, such a threat is not credible. Thus, the incumbent must

make his or her threat of a price war believable by signaling to the potential entrant

that a price war will result if entry occurs. One strategic move is to increase capacity,

signaling a lower future price, and another is to engage in apparently irrational

behavior. Both types of strategic behavior might deter entry, but for different reasons.

While an increase in capacity reduces expected profits by reducing prices, irrational

behavior reduces expected profits by increasing uncertainty, hence increasing the rate

at which future profits must be discounted into the present.

11. A strategic move limits one’s flexibility and yet gives one an advantage. Why? How might a strategic move give one an advantage in bargaining?

A strategic move influences conditional behavior by the opponent. If the game is well

understood and the opponent’s reaction can be predicted, a strategic move leaves the

player better off. Economic transactions involve a bargain, whether implicit or

explicit. In every bargain, we assume that both parties attempt to maximize their

self-interest. Strategic moves by one player provide signals to which another player

reacts. If a bargaining game is played only once (so no reputations are involved), the

players might act strategically to maximize their payoffs. If bargaining is repeated,

players might act strategically to establish reputations for expected negotiations.

1. In many oligopolistic industries, the same firms compete over a long period of time, setting prices and observing each other’s behavior repeatedly. Given that the number of repetitions is large, why don’t collusive outcomes typically result?

If games are repeated indefinitely and all players know all payoffs, rational behavior

will lead to apparently collusive outcomes, i.e., the same outcomes that would result if

firms were actively colluding. All payoffs, however, might not be known by all players.

Sometimes the payoffs of other firms can only be known by engaging in extensive (and

costly) information exchanges or by making a move and observing rivals’ responses.

Also, successful collusion encourages entry. Perhaps the greatest problem in

maintaining a collusive outcome is that changes in market conditions change the

collusive price and quantity. The firms then have to repeatedly change their

agreement on price and quantity, which is costly, and this increases the ability of one

firm to cheat without being discovered.

2. Many industries are often plagued by overcapacity--firms simultaneously make major investments in capacity expansion, so total capacity far exceeds demand. This happens in industries in which demand is highly volatile and unpredictable, but also in industries in which demand is fairly stable. What factors lead to overcapacity? Explain each briefly.

In Chapter 12, we found that excess capacity may arise in industries with easy entry

and differentiated products. In the monopolistic competition model, downward-sloping

demand curves for each firm lead to output with average cost above minimum average

cost. The difference between the resulting output and the output at minimum

long-run average cost is defined as excess capacity. In this chapter, we saw that

overcapacity could be used to deter new entry; that is, investments in capacity

expansion could convince potential competitors that entry would be unprofitable.

(Note that although threats of capacity expansion may deter entry, these threats must

be credible.)

3. Two computer firms, A and B, are planning to market network systems for office information management. Each firm can develop either a fast, high-quality system (H), or a slower, low-quality system (L). Market research indicates that the resulting profits to each firm for the alternative strategies are given by the following payoff matrix:

Firm B

H L

H

Firm A

L

a. If both firms make their decisions at the same time and follow maximin(low-risk)

strategies, what will the outcome be?

With a maximin strategy, a firm determines the worst outcome for each option, then

chooses the option that maximizes the payoff among the worst outcomes. If Firm A

chooses H, the worst payoff would occur if Firm B chooses H: A’s payoff would be 30. If

Firm A chooses L, the worst payoff would occur if Firm B chooses L: A’s payoff would be

20. With a maximin strategy, A therefore chooses H. If Firm B chooses L, the worst

payoff would occur if Firm A chooses L: the payoff would be 20. If Firm B chooses H, the

worst payoff, 30, would occur if Firm A chooses L. With a maximin strategy, B

therefore chooses H. So under maximin, both A and B produce a high-quality system.

b. Suppose both firms try to maximize profits, but Firm A has a head start in planning,

and can commit first. Now what will the outcome be? What will the outcome be if Firm B has a head start in planning and can commit first?

If Firm A can commit first, it will choose H, because it knows that Firm B will rationally

choose L, since L gives a higher payoff to B (35 vs. 30). This gives Firm A a payoff of

50. If Firm B can commit first, it will choose H, because it knows that Firm A will

rationally choose L, since L gives a higher payoff to A (40 vs. 30). This gives Firm B a

payoff of 60.

c. Getting a head start costs money (you have to gear up a large engineering team).

Now consider the two-stage game in which first, each firm decides how much money to spend to speed up its planning, and second, it announces which product (H or L) it will produce. Which firm will spend more to speed up its planning? How much will it spend? Should the other firm spend anything to speed up its planning? Explain.

In this game, there is an advantage to being the first mover. If A moves first, its profit

is 50. If it moves second, its profit is 40, a difference of 10. Thus, it would be willing to

spend up to 10 for the option of announcing first. On the other hand, if B moves first,

its profit is 60. If it moves second, its profit is 35, a difference of 25, and thus would be

willing to spend up to 25 for the option of announcing first. Once Firm A realizes that

Firm B is willing to spend more on the option of announcing first, then the value of the

option decreases for Firm A, because if both firms were to invest both firms would

choose to produce the high-quality system. Therefore, Firm A should not spend money

to speed up the introduction of its product if it believes that Firm B is spending the

money. However, if Firm B realizes that Firm A will wait, Firm B should only spend

enough money to discourage Firm A from engaging in research and development, which

would be an amount slightly more than 10 (the maximum amount A is willing to

spend).

4. Two firms are in the chocolate market. Each can choose to go for the high end of the market (high quality) or the low end (low quality). Resulting profits are given by the following payoff matrix:

Firm 2

Low High

Low

Firm 1

High

a. What outcomes, if any, are Nash equilibria?

If Firm 2 chooses Low and Firm 1 chooses High, neither will have an incentive to

change (100 > -20 for Firm 1 and 800 > 50 for Firm 2). If Firm 2 chooses High and

Firm 1 chooses Low, neither will have an incentive to change (900 > 50 for Firm 1 and

600 > -30 for Firm 2). Both outcomes are Nash equilibria.

b. If the manager of each firm is conservative and each follows a maximin strategy,

what will be the outcome?

If Firm 1 chooses Low, its worst payoff, -20, would occur if Firm 2 chooses Low. If Firm

1 chooses High, its worst payoff, 50, would occur if Firm

2 chooses High. Therefore, with

a conservative maximin strategy, Firm 1 chooses High. Similarly, if Firm 2 chooses

Low, its worst payoff, -30, would occur if Firm 1 chooses Low. If Firm 2 chooses High, its

worst payoff, 50, would occur if Firm 1 chooses High. Therefore, with a maximin

strategy, Firm 2 chooses High. Thus, both firms choose High, yielding a payoff of 50 for

both.

c. What is the cooperative outcome?

The cooperative outcome would maximize joint payoffs. This would occur if Firm 1

goes for the low end of the market and Firm 2 goes for the high end of the market. The

joint payoff is 1,500 (Firm 1 gets 900 and Firm 2 gets 600).

d. Which firm benefits most from the cooperative outcome? How much would that

firm need to offer the other to persuade it to collude?

Firm 1 benefits most from cooperation. The difference between its best payoff under

cooperation and the next best payoff is 900 - 100 = 800. To persuade Firm 2 to choose

Firm 1’s best option, Firm 1 must offer at least the difference between Firm 2’s payoff

under cooperation, 600, and its best payoff, 800, i.e., 200. However, Firm 2 realizes

that Firm 1 benefits much more from cooperation and should try to extract as much as

it can from Firm 1 (up to 800).

5. Two major networks are competing for viewer ratings in the 8:00-9:00 P.M. and 9:00-10:00 P.M. slots on a given weeknight. Each has two shows to fill this time period and is juggling its lineup. Each can choose to put its “bigger” show first or to plac e it second in the 9:00-10:00 P.M. slot. The combination of decisions leads to the following “ratings points” results:

Network 2

First

Network 1

Second

a. Find the Nash equilibria for this game, assuming that both networks make their

decisions at the same time.

A Nash equilibrium exists when neither party has an incentive to alter its strategy,

taking the other’s strategy as given. By inspecting each of the four combinations, we

find that (First, Second) is the only Nash equilibrium, yielding a payoff of (23, 20).

There is no incentive for either party to change from this outcome.

b. If each network is risk averse and uses a maximin strategy, what will be the resulting

equilibrium?

This conservative strategy of minimizing the maximum loss focuses on limiting the

extent of the worst possible outcome, to the exclusion of possible good outcomes. If

Network 1 plays First, the worst payoff is 18. If Network 1 plays Second, the worst

payoff is 4. Under maximin, Network 1 plays First. (Here, playing First is a

dominant strategy.) If Network 2 plays First, the worst payoff is 18. If Network 2

plays Second, the worst payoff is 16. Under maximin, Network 2 plays First. The

maximin equilibrium is (First, First) with a payoff of (18,18).

c. What will be the equilibrium if Network 1 can makes its selection first? If Network 2

goes first?

If Network 1 plays First, Network 2 will play Second, yielding 23 for Network 1. If

Network 1 plays Second, Network 2 will play First, yielding 4 for Network 1.

Therefore, if it has the first move, Network 1 will play First, and the resulting

equilibrium will be (First, Second). If Network 2 plays First, Network 1 will play First,

yielding 18 for Network 2. If Network 2 plays Second, Network 1 will play First,

yielding 20 for Network 2. If it has the first move, Network 2 will play Second, and the

equilibrium will again be (First, Second).

d. Suppose the network managers meet to coordinate schedules, and Network 1

promises to schedule its big show first. Is this promise credible, and what would be the likely outcome?

A move is credible if, once declared, there is no incentive to change. Network 1 has a

dominant strategy: play the bigger show First. In this case, the promise to schedule

the bigger show first is credible. Knowing this, Network 2 will schedule its bigger

show Second. The coordinated outcome is likely to be (First, Second).

6. Two competing firms are each planning to introduce a new product. Each firm will decide whether to produce Product A, Product B, or Product C. They will make their choices at the same time. The resulting payoffs are shown below.

We are given the following payoff matrix, which describes a product introduction game:

Firm 2

A B C

A

Firm 1 B

C

a. Are there any Nash equilibria in pure strategies? If so, what are they?

There are two Nash equilibria in pure strategies. Each one involves one firm introducing Product A and the other firm introducing Product C. We can write these two strategy pairs as (A, C) and (C, A), where the first strategy is for player 1. The payoff for these two strategies is, respectively, (10,20) and (20,10).

b. If both firms use maximin strategies, what outcome will result?

Recall that maximin strategies maximize the minimum payoff for both players. For each of the players the strategy that maximizes their minimum payoff is A. Thus (A,A) will result, and payoffs will be (-10,-10). Each player is much worse off than at either of the pure strategy Nash equilibrium.

c. If Firm 1 uses a maximin strategy, and Firm 2 knows, what will Firm 2 do?

If Firm 1 plays its maximin strategy of A, and Firm 2 knows this then Firm 2 would get the highest payoff by playing C. Notice that when Firm 1 plays conservatively, the Nash equilibrium that results gives Firm 2 the highest payoff of the two Nash equilibria.

7. We can think of the U.S. and Japanese trade policies as a Prisoners’ Dilemma. The two countries are considering policies to open or close their import markets. Suppose the payoff matrix is:

Japan

Open

U.S.

Close

a. Assume that each country knows the payoff matrix and believes that the other

country will act in its own interest. Does either country have a dominant strategy?

What will be the equilibrium policies if each country acts rationally to maximize its welfare?

Choosing Open is a dominant strategy for both countries. If Japan chooses Open, the

U.S. does best by choosing Open. If Japan chooses Close, the U.S. does best by

choosing Open. Therefore, the U.S. should choose Open, no matter what Japan does.

If the U.S. chooses Open, Japan does best by choosing Open. If the U.S. chooses Close,

Japan does best by choosing Open. Therefore, both countries will choose to have Open

policies in equilibrium.

b. Now assume that Japan is not certain that the U.S. will behave rationally. In

particular, Japan is concerned that U.S. politicians may want to penalize Japan even

if that does not maximize U.S. welfare. How might this affect Japan’s choice of strategy? How might this change the equilibrium?

The irrationality of U.S. politicians could change the equilibrium from (Close, Open).

If the U.S. wants to pen alize Japan they will choose Close, but Japan’s strategy will not

be affected since choosing Open is still Japan’s dominant strategy.

8. You are a duopolist producer of a homogeneous good. Both you and your competitor have zero marginal costs. The market demand curve is

P = 30 - Q

where Q = Q 1 + Q 2. Q 1 is your output and Q 2 is your competitor’s output. Your competitor has also read this book.

a. Suppose you are to play this game only once. If you and your competitor must

announce your output at the same time, how much will you choose to produce? What do you expect your profit to be? Explain.

These are some of the cells in the payoff matrix:

Firm 2’s Output

Firm 1’s

Output 0

5

10

15

20

25

30 If both firms must announce output at the same time, both firms believe that the other

firm is behaving rationally, and each firm treats the output of the other firm as a fixed

number, a Cournot equilibrium will result.

For Firm 1, total revenue will be

TR 1 = (30 - (Q 1 + Q 2))Q 1, or TR Q Q Q Q 1112

1230=--.

Marginal revenue for Firm 1 will be the derivative of total revenue with respect to Q 1, ?? TR Q Q Q 1

12302=--. Because the firms share identical demand curves, the solution for Firm 2 will be

symmetric to that of Firm 1:

?? TR Q Q Q 2

21302=--. To find the profit-maximizing level of output for both firms, set marginal revenue equal

to marginal cost, which is zero:

Q Q 12152

=- and Q Q 21152

=-. With two equations and two unknowns, we may solve for Q 1 and Q 2:

()??? ?

?--=2155.01511Q Q , or Q 1 = 10. By symmetry, Q 2 = 10.

Substitute Q 1 and Q 2 into the demand equation to determine price:

P = 30 - (10 + 10), or P = $10.

Since no costs are given, profits for each firm will be equal to total revenue:

π1 = TR 1 = (10)(10) = $100 and

π2 = TR 2 = (10)(10) = $100.

Thus, the equilibrium occurs when both firms produce 10 units of output and both firms

earn $100. Looking back at the payoff matrix, note that the outcome (100, 100) is

indeed a Nash equilibrium: neither firm will have an incentive to deviate, given the

other firm’s choice.

b. Suppose you are told that you must announce your output before your competitor

does. How much will you produce in this case, and how much do you think your competitor will produce? What do you expect your profit to be? Is announcing first an advantage or disadvantage? Explain briefly. How much would you pay to be given the option of announcing either first or second?

If you must announce first, you would announce an output of 15, knowing that your

competitor would announce an output of 7.5. (Note: This is the Stackelberg

equilibrium.)

()()21521530302

11112

111211Q Q Q Q Q Q Q Q Q TR -=??? ??---=+-=. Therefore, setting MR = MC = 0 implies:

15 - Q 1 = 0, or Q 1 = 15 and

Q 2 = 7.5.

At that output, your competitor is maximizing profits, given that you are producing 15.

At these outputs, price is equal to

30 - 15 - 7.5 = $7.5.

Your profit would be

(15)(7.5) = $112.5.

Your competitor’s profit would be

(7.5)(7.5) = $56.25.

Announcing first is an advantage in this game. The difference in profits between

announcing first and announcing second is $56.25. You would be willing to pay up to

this difference for the option of announcing first.

c. Suppose instead that you are to play the first round of a series of 10 rounds (with the

same competitor). In each round, you and your competitor announce your outputs at the same time. You want to maximize the sum of your profits over the 10 rounds. How much will you produce in the first round ? How much would you expect to produce in the tenth round? The ninth round? Explain briefly.

Given that your competitor has also read this book, you can assume that he or she will

be acting rationally. You should begin with the Cournot output and continue with the

Cournot output in each round, including the ninth and tenth rounds. Any deviation

from this output will reduce the sum of your profits over the ten rounds.

d. Once again you will play a series of 10 rounds. This time, however, in each round

your competitor will announce its output before you announce yours. How will your answers to (c) change in this case?

If your competitor always announces first, it might be more profitable to behave by

reacting “irrationally” in a single period. Fo r example, in the first round your

competitor will announce an output of 15, as in Exercise (7.b). Rationally, you would

respond with an output of 7.5. If you behave this way in every round, your total profits

for all ten rounds will be $562.50. Your co mpetitor’s profits will be $1,125. However, if

you respond with an output of 15 every time your competitor announces an output of 15,

profits will be reduced to zero for both of you in that period. If your competitor fears, or

learns, that you will respond in this way, he or she will be better off by choosing the

Cournot output of 10, and your profits after that point will be $75 per period. Whether

this strategy is profitable depends on your opponent’s expectations about your behavior,

as well as how you value future profits relative to current profits.

(Note: A problem could develop in the last period, however, because your competitor will

know that you realize that there are no more long-term gains to be had from behaving

strategically. Thus, your competitor will announce an output of 15, knowing that you

will respond with an output of 7.5. Furthermore, knowing that you will not respond

strategically in the last period, there are also no long-term gains to be made in the ninth

period from behaving strategically. Therefore, in the ninth period, your competitor will

announce an output of 15, and you should respond rationally with an output of 7.5, and

so on.)

9. You play the following bargaining game. Player A moves first, and makes Player B an offer for the division of $100. (For example, Player A could suggest that she take $60 and Player B take $40). Player B can accept or reject the offer. If he rejects, the amount of money available drops to $90, and he then makes an offer for the division of this amount. If Player A rejects this offer, the amount of money drops to $80, and Player A makes an offer for its division. If Player B rejects this offer, the amount of money drops to 0. Both players are rational, fully informed, and want to maximize their payoffs. Which player will do best in this game?

Solve the game by starting at the end and working backwards. If B rejects A’s offer

at the 3rd round, B gets 0. When A makes an offer at the 3rd round, B will accept even

a minimal amount, such as $1. So A should offer $1 at this stage and take $79 for

herself. In the 2nd stage, B knows that A will turn down any offer giving her less

than $79, so B must offer $80 to A, leaving $10 for B. At the first stage, A knows B

will turn down any offer giving him less than $10. So A can offer $11 to B and keep

$89 for herself. B will take that offer, since B can never do any better by rejecting

and waiting. The following table summarizes this.

Round Money Offering Party Amount to A Amount to B

Available

1 $100 A $89 $11

2 $ 90 B $80 $10

3 $ 80 A $79 $ 1

End $ 0 $ 0 $ 0

*10. Defendo has decided to introduce a revolutionary video game, and as the first firm in the market, it will have a monopoly position for at least some time. In deciding what type of manufacturing plant to build, it has the choice of two technologies. Technology A is publicly available and will result in annual costs of

C A(q) = 10 + 8q.

Technology B is a proprietary technology developed in Defendo’s research labs. It involves higher fixed cost of production, but lower marginal costs:

C B(q) = 60 + 2q.

Defendo’s CEO must decide which technology to adopt. Market demand for the new product is P = 20 - Q, where Q is total industry output.

a. Suppose Defendo were certain that it would maintain its monopoly position in the

market for the entire product lifespan (about five years) without threat of entry. Which technology would you advise the CEO to adopt? What would be Defendo’s profit given this choice?

Defendo has two choices: Technology A with a marginal cost of 8 and Technology B with

a marginal cost of 2. Given the inverse demand curve as P = 20 - Q , total revenue, PQ ,

is equal to 20Q - Q 2 for both technologies. Marginal revenue is 20 - 2Q . To determine

the profits for each technology, equate marginal revenue and marginal cost:

20 - 2Q A = 8, or Q A = 6, and

20 - 2Q B = 2, or Q B = 9.

Substituting the profit-maximizing quantities into the demand equation to determine

the profit-maximizing prices, we find:

P A = 20 - 6 = $14 and

P B = 20 - 9 = $11.

To determine the profits for each technology, subtract total cost from total revenue:

πA = (14)(6) - (10 + (8)(6)) = $26 and

πB = (11)(9) - (60 + (2)(9)) = $21.

To maximize profits, Defendo should choose technology A.

b. Suppose Defendo expects its archrival, Offendo, to consider entering the market

shortly after Defendo introduces its new product. Offendo will have access only to Technology A. If Offendo does enter the market, the two firms will play a Cournot game (in quantities) and arrive at the Cournot-Nash equilibrium.

i. If Defendo adopts Technology A and Offendo enters the market, what will be the profits of both firms? Would Offendo choose to enter the market given these profits? If both firms play Cournot, each will cho ose its best output, taking the other’s strategy as

given. Letting D = Defendo and O = Offendo, the demand function will be

P = 20 - Q D - Q O .

Profit for Defendo will be

()()D D O D D Q Q Q Q 81020+---=π, or πD D D

D O Q Q Q Q =---12102 To determine the profit-maximizing quantity, set the first derivative of profits with

respect to Q D equal to zero and solve for Q D :

?π?D D

D O Q Q =--=1220, or Q D = 6 - 0.5Q O . This is Defendo’s reaction function. Because both firms have access to the same

technology, hence the same cost structu re, Offendo’s reaction function is analogous:

Q O = 6 - 0.5Q D .

Substituting Offendo’s reaction function into Defendo’s reaction function and solving for

Q D :

Q D = 6 - (0.5)(6 - 0.5Q D ) = 4.

Substituting into Defendo’s reaction function and solving for Q O :

Q O = 6 - (0.5)(4) = 4.

Total industry output is therefore equal to 8. To determine price, substitute Q D and

Q O into the demand function:

P = 20 - 4 - 4 = $12.

The profits for each firm are equal to total revenue minus total costs:

πD = (4)(12) - (10 + (8)(4)) = $6 and

πO = (4)(12) - (10 + (8)(4)) = $6.

Therefore, Offendo would enter the market.

ii. If Defendo adopts Technology B and Offendo enters the market, what will be the profit of each firm? Would Offendo choose to enter the market given these profits?

Profit for Defendo will be

()()D D O D D Q Q Q Q 26020+---=π, or πD D D

D O Q Q Q Q =---18602. The change in profit with respect to Q D is

?π? D D

D O Q Q Q =--182. To determine the profit-maximizing quantity, set this derivative to zero and solve for Q D :

18 - 2Q D - Q O = 0, or Q D = 9 - 0.5Q O .

This is Defendo’s reaction function. Substituting Offendo’s reaction function into

Defendo’s reaction function and solving for Q D :

Q D = 9 - 0.5(6 - 0.5Q D ), or Q D = 8.

Substituting Q D into Offendo’s reaction function yields

Q O = 6 - (0.5)(8), or Q O = 2.

To determine the industry price, substitute the profit-maximizing quantities for Defendo

and Offendo into the demand function:

P = 20 - 8 - 2 = $10.

The profit for each firm is equal to total revenue minus total cost, or:

πD = (10)(8) - (60 + (2)(8)) = $4 and

πO = (10)(2) - (10 + (8)(2)) = -$6.

With negative profit, Offendo should not enter the industry.

iii. Which technology would you advise the CEO of Defendo to adopt given the threat of possible entry? What will be Defe ndo’s profit given this choice? What will be consumer surplus given this choice?

With Technology A and Offendo’s entry, Defendo’s profit would be 6. With Technology

B and no entry by Defendo, Defendo’s profit would be 4. I would advise Defendo to stick

with Technology A. Under this advice, total output is 8 and price is 12. Consumer

surplus is:

(0.5)(20 -12)(8) = $32.

c. What happens to social welfare (the sum of consumer surplus and producer profit) as

a result of the threat of entry in this market? What happens to equilibrium price? What might this imply about the role of potential competition in limiting market power?

From 10.a we know that, under monopoly, Q = 6 and profit is 26. Consumer surplus is

(0.5)(20 - 14)(6) = $18.

Social welfare is the sum of consumer surplus plus profits, or

18 + 26 = $44.

With entry, social welfare is $32 (consumer surplus) plus $12 (industry profit), or $44.

Social welfare changes little with entry, but entry shifts surplus from producers to

consumers. The equilibrium price falls with entry, and therefore potential competition

can limit market power.

Note that Defendo has one other option: to increase quantity from the monopoly level of

6 to discourage entry by Offendo. If Defendo increases output from 6 to 8 under

Technology A, Offendo is unable to earn a positive profit. With an output of 8,

Defendo’s profit decreases from $26 to

(8)(12) - (10 + (8)(8)) = $22.

As before, with an output of 8, consumer surplus is $32; social welfare is $54. In this

case, social welfare rises when output is increased to discourage entry.

11. Three contestants, A, B, and C, each have a balloon and a pistol. From fixed positions, they fire at each other’s balloon. When a balloon is hit, its owner is out. When only one balloon remains, its owner is the winner and receives a $1,000 prize. At the outset, the players decide by lot the order in which they will fire, and each player can choose any remaining balloon as his target. Everyone knows that A is the best shot and always hits the target, that B hits the target with probability .9, and that C hits the target with probability 0.8. Which contestant has the highest probability of winning the $1,000? Explain why.

Intuitively, C has the highest probability of winning, though A has the highest

probability of shooting the balloon. Each contestant wants to remove the contestant

with the highest probability of success. By following this strategy, each improves his

chance of winning the game. A targets B because, by removing B from the game, A’s

chance of winning becomes much greater. B’s probability of success is greater than C’s

probability of success. C will target A because, if C targets B and hits B, then A will

target C and win the game. B will follow a similar strategy, because if B targets C and

hits C, then A will target B and will win the game. Therefore, both B and C increase

their chance of winning by eliminating A first. Similarly, A increases his chance of

winning by eliminating B first. A complete probability tree can be constructed to show

that A’s chance of winning is 8 percent, B’s chance of winning is 32 percent, and C’s

chance of winning is 60 percent.

CHAPTER 14

MARKETS FOR FACTOR INPUTS

In the following two chapters, we examine markets for labor and capital. Although the discussion in this chapter is general, most of the examples refer to labor as the only variable input to production, with the exception of Example 14.1, which discusses “The Demand for Jet Fuel” by airlines. The demand and supply for labor is explored in the first section, and the competitive factor market equilibrium and economic rent are discussed in the second. Exercises (1)-(3), (5), and (7) require familiarity with these two sections. The last two sections discuss imperfect factor markets. While Exercises (4) and (8) consider the monopolization of the labor market, Exercise (6) focuses on monopsony power.

An understanding of this chapter relies on concepts from Chapters 4 through 8 and 10. Given that this chapter covers subjects different from those of the immediately preceding chapters (11 - 13), you should begin by reviewing marginal product, marginal revenue, and cost minimization. You should then discuss marginal revenue product and the profit-maximizing condition, MRP

= w.

L Explain why we are only interested in the portion of the MP curve below the average product curve (the downward-sloping portion). If students remember Chapters 6, 7, and 8, they should have no problem deriving the firm’s demand curve for labor.But “The Demand for a Factor Input When Several Inputs

Are Variable” is not as easy. In particular, explain why the MRP L shifts as the firm substitutes one input for another in production in response to a price change. Since each MRP curve represents a different level of the fixed factor, the marginal product of the variable factor changes as the fixed factor varies. As a precursor to Chapter 16, stress the importance of paying inputs the value of their marginal product.

When presenting the market demand curve, explain that since the input prices change as more inputs are demanded, the market demand curve is not simply the summation of individual demand curves. You can extend the presentation of price elasticity of input demand (see Example 14.1) by discussing the conditions leading to price sensitivity. Elasticity is greater (1) when the elasticity of demand for the product is higher, (2) when it is easy to substitute one input for another, and (3) when the elasticity of supply is higher for other inputs. Elasticity of supply, which was discussed in Chapter 2, is reintroduced in Example 14.2. You should also distinguish between short-run and long-run elasticity (see Figure 14.6).

If you have already covered substitution and income effects, the students will be ready for the derivation of the backward-bending supply curve for labor. Although Figure 14.9 is a straightforward application of these tools, students are confused by the plotting of income against leisure. Remind students that the 24-hour limit is arbitrary. Any time period may be used, e.g., one year or a lifetime (see Exercise (1). The following chart might help students when the supply curve for an individual’s labor is backward bending:

Leisure is

Normal Good Inferior Good Income Effect > Substitution Effect

Yes No Income Effect = 0 No No

An individual’s supply curve of labor is backward bending only when the income effect dominates the substitution effect and leisure is a normal good. You may discuss the elasticity of input supply by referring to Example 14.2. Show typical supply curves for each group in Table 14.2. For an experimental study of the labor-leisure trade-off see Battalio, Green, and Kagel, “Income -Leisure Tradeoff of Animal Workers,” American Economic Review (September 1981).

Section 14.2 brings together labor demand and supply for both competitive and monopolistic product markets. Although economic rent was presented in Chapter 8, it is reintroduced with more detail here. Sections 14.3 and 14.4 present imperfect factor markets. Carefully explain why the marginal expenditure curve is above the average expenditure curve for a monopsonist (see Figure 14.14). You can discuss how a monopsonist would price discriminate, e.g., pay a different wage rate to each employee. With perfect price discrimination, the marginal revenue expenditure curve would coincide with the average expenditure curve. Although monopsony exists in some markets, the exercise of monopsony power is rare because of factor mobility. However, the employment of athletes by the owners of professional teams provides a good example. See Example 14.4 “Monopsony Power in the Market for Baseball Players.” On this same topic, see Sommers and Quinton, “Pay and Performance in Major League Baseball: The Case of the First Family of Free Agents,” Journal of Human Resources (Summer 1982).

1. Why is a firm’s demand - for-labor curve more inelastic when the firm has monopoly power in the output market than when the firm is producing competitively?

The firm’s demand curve for labor is determined by the incremental revenue from

hiring an additional unit of labor known as the marginal revenue product of labor:

MRP L = (MP L )(MR ), the additional output (“product”) that the last worker produced,

times the additional revenue earned by selling that output. In a competitive industry,

the marginal revenue curve is perfectly elastic and equal to price. For a monopolist,

marginal revenue is downward sloping. This implies that the marginal revenue

product for the monopolist is more inelastic than for the competitive firm.

2. Why might a labor supply curve be backward bending?

A backward-bending supply curve for labor may occur when the income effect of an

increase in the wage rate dominates the substitution effect. Labor supply decisions are

made by individuals choosing the most satisfying combination of work and other

activities. With a larger income, the individual can afford to work fewer hours: the

income effect. But as the wage rate increases, the value of leisure time (the

opportunity cost of leisure) increases, thus inducing the individual to work longer

hours: the substitution effect. Because the two effects work in opposite directions, the

shape of an individual’s labor supply curve depends on the individual’s preferences for

income, consumption, and leisure.

3. How is a computer company’s demand for computer programmers a derived demand?

A computer company’s demand for inputs, including programmers, depends on how

many computers it sells. The firm’s demand for programming labor depends on (is

derived from) the demand it faces in its market for computers. As demand for

computers shifts, the demand for programmers shifts.

4. Compare the hiring choices of a monopsonistic and a competitive employer of workers. Which will hire more workers, and which will pay the higher wages? Explain.

Because the monopsonist pays a higher wage for all workers as employment increases

(not just the last worker hired), its marginal expenditure curve lies above the input

supply curve (the average expenditure curve). The monopsonist’s profit-maximizing

input demand, where the marginal expenditure curve intersects the marginal revenue

product curve, will be less than the competitor’s profit-maximizing input choice, where

the average expenditure curve intersects the demand curve. The monopsonist hires

less labor, and the wage paid will be less than in a competitive market.

5. Rock musicians sometimes earn over $1 million per year. Can you explain this large income in terms of economic rent?

With top-quality rock musicians (who will continue to play rock music no matter what

they are paid) in fixed supply, the economic rent will be the difference between $1

million and the amount below which they would stop playing rock-and-roll.

6. What happens to the demand for one input when the use of a complementary input increases?

If the demand for an input increases, the demand for complementary inputs increases

as well. To determine the total change in demand, one must consider changes in prices

and marginal products of all complementary inputs.

7. For a monopsonist, what is the relationship between the supply of an input and the marginal expenditure on that input?

When a monopsonist increases employment, it must pay all units the higher price, not

just the last unit hired; therefore, its marginal expenditure curve lies above the input

supply curve (the average expenditure curve).

8. Currently the National Football League has a system for drafting college players by which each player is picked by only one team and must sign with that team or not play in the league. What would happen to the wages of newly drafted and more experienced football players if the draft system were repealed, so that all teams could compete for college players?

The National Football League draft and reserve clause (a primary issue in the

1987-1988 season’s strike) creates a monopsonist cartel among the owners of NFL

teams. If the draft system were repealed, competition among teams would increase

wages of football players to the point where the marginal revenue product of each

player would be equal to the player’s wage.

9. Why are wages and employment levels indeterminate when the union has monopoly power and the firm has monopsony power?

When the only seller of an input, a monopolist, faces the only buyer of the input, a monopsonist, the monopolist maximizes profits by setting input supply at a point where marginal revenue is equal to marginal cost, while the monopsonist maximizes profits at the point where marginal expenditure is equal to marginal cost. Thus, the monopolist asks for a price above marginal revenue while the monopsonist offers a price below marginal expenditure. The actual transaction price will be the result of negotiations and will depend on the relative bargaining strengths of the two parties.

5,000 2,500 2,500 5,000

6,000 3,000 2,000 5,000

7,000 3,500 1,500 5,000

8,000 4,000 1,000 5,000

9,000 4,500 500 5,000

10,000 5,000 0 5,000

2. Using your knowledge of marginal revenue product, explain the following:

a. A famous tennis star is paid $100,000 for appearing in a 30-second television

commercial. The actor who plays his doubles partner is paid $500.

, is equal to marginal revenue from an Marginal revenue product of labor, MRP

L

incremental unit of output multiplied by the marginal product from an incremental unit

of labor. In 2a, the advertiser is willing to increase expenditures on advertising until

an extra dollar on advertising and the extra cost of production are equal to the extra

revenue from increased sales. The famous tennis star is able to help increase revenues

far more than the actor. In equilibrium, the tennis star helps generate $100,000 in

revenue. The wage of the actor is determined by the supply and demand of actors

willing to play tennis with tennis stars.

b. The president of an ailing savings and loan is paid not to hold office for the last two

years of his contract.

The marginal revenue product of the president of the ailing savings and loan is

negative; therefore, the savings and loan is better off by paying the president not to

show up.

c. A jumbo jet carrying 400 passengers is priced higher than a 250-passenger model

even though both aircraft cost the same to manufacture.

The ability of the larger jet to generate more revenue increases its value to the airline,

and therefore the airline is willing to pay more for it.

3. The demand for the factors of production listed below have increased. What can you conclude about changes in the demand for the related consumer goods? If demands for the consumer goods remain unchanged, what other explanation is there for an increase in derived demands for these items?

a. Computer memory chips

An increase in the demand for a good increases the demand for its factor inputs. The

converse is not necessarily true; i.e., an increase in the demand for factor inputs does

not necessarily imply an increase in the demand for the final product. The demand for

an input may increase due to a change in the use of other inputs in the production

process. As the price of another input increases, its demand falls and the demand of

substitutable inputs rises. With the increased demand for personal computers, the

demand for memory chips has increased.

b. Jet fuel for passenger planes

With an increase in the demand for jet travel, the demand for jet fuel will increase.

c. Paper used for newsprint

If the circulation of newspapers increases, the demand for newsprint will increase.

d. Aluminum used for beverage cans

With an increase in demand for cold drinks in the summer, the seasonal demand for

aluminum increases. If aluminum demand has increased because of its recyclable

properties, the demand for aluminum will increase permanently.

4. Suppose there are two groups of workers, unionized and nonunionized. Congress passes a law that requires all workers to join the union. What do you expect to happen to the wage rates of formerly nonunionized workers and those workers who were originally unionized? What have you assumed about the union’s behavior?

After workers are required to join the union, wages will depend on the union’s objective,

e.g., whether to maximize the wage rate or maximize employment. If the union wage

is unchanged, the wage rate of some of the previously nonunionized workers will rise to

the union wage rate while the wage rates of other previously nonunionized workers will

fall to zero as employers reduce their hiring. In addition, wages of previously

implications of the government’s m onopsony power: fewer soldiers are hired, and they

are paid less than their marginal product. When a mandatory draft is implemented,

even fewer professional soldiers are hired. Wages for volunteer soldiers fall, pushed

down by the fact that wages of the draftees can be very low.

7. The demand for labor by an industry is given by the curve L = 1200 - 10w, where L is the labor demanded per day, and w is the wage rate. The supply curve is given by L = 20w. What is the equilibrium wage rate and quantity of labor hired? What is the economic rent earned by workers?

The equilibrium wage rate is determined where quantity of labor supplied is equal to

the quantity of labor demanded:

20w = 1,200 - 10w, or w = $40.

curve up, in Figure 14.8, to the labor demanded at w.

To maximize rent, the union will choose the number of workers hired, so that the marginal revenue to the union (the additional wages earned) is equal to the extra cost of inducing the worker to work. This involves choosing the quantity of labor at the point where the marginal revenue curve crosses the supply curve of labor.

Setting the marginal revenue curve equal to the supply curve for labor, we find:

600 - 5w = 20w, or w* = 24.

At w*, we may determine the number of workers who are willing to work by substituting w* into the labor supply equation:

L* = (20)(24) = 480.

Therefore, if the union wants to maximize the rent that the union members earn, the union should limit employment to 480 members.

平狄克微观经济学课后习题答案-第7-8章

第七章 复习题 1.显性成本 2.她自己做其他事时会得到的最高收入 3.多用资本,少用工人 4.完全竞争价格给定,即斜率不变 5.不意味 6.意味着递增 7.AVC

第七章附录 练习题 1、我们考查规模报酬时可由F（aK，aL）与aF（K，L）之间的关系判断 当F（aK，aL）>aF（K，L）,表明是规模报酬递增； 当F（aK，aL）=aF（K，L）,表明是规模报酬不变； 当F（aK，aL）

平狄克微观经济学知识点

平狄克微观经济学知识点（原创）2012-7-23 20:22阅读(365)赞(6)转载(26)分享(15)评论(13)复制地址举报更多已经是第一篇下一篇：高鸿业宏观经济学... 平狄克微观经济学知识点 第一章绪论 此章不是重点内容，能够区别实证分析和规范分析即可，课后题可以不用做。 第二章供给和需求的基本原理 本章是微观的基础性知识，要求理解记忆，掌握供求变动的基本原理，其中短期弹性和长期弹性这个知识点高鸿业的教材上貌似没有，要特别注意。 课后复习题：重点做4、5、8、11 课后练习题：重点做5、9、10 第三章消费者行为 本章属于重点知识，其中无差异曲线、边际替代率、预算线、生活成本指数都是重要的概念，要求能够理解掌握。 课后复习题：重点做2、3、5、6、12 课后练习题：没有特别重要的题目 第四章个人需求和市场需求 除第6部分需求的经验估计之外，其余都是重要知识点。 课后复习题：重点做12 课后练习题：重点做7，其余没有特别重要的 第四章附录需求理论——一种数学的处理方法 本章的重点在于根据效用函数求需求函数，掌握此知识点即可。 第五章不确定性与消费者行为 除第4部分对风险资产的需求之外，其余都是重要知识点。 课后复习题：做10题，里面有个重要的概念“捐赠效应”，即“禀赋效应”。 课后练习题：第6题 第六章生产 都是重要知识点，其中生产函数，等产量线，规模报酬等是重要的概念。 课后练习题：重点做1、3、7、12 课后练习题：重点做8、9 第七章生产成本 都是重要内容，可能会出计算题。其中经济成本、沉没成本、等成本线、规模经济和规模不

经济、范围经济、学习曲线可能会出名词解释。 课后复习题：重点做11、12、13、14 课后练习题：重点做8、9、11、12、13 第七章附录生产和成本理论——一个数学的处理 课后题1、2、3可以做做，不难。 第八章利润的最大化和竞争性供给 是重点章节，完全竞争市场可能会出计算，生产者剩余、行业的长期供给曲线可能会出名词解释。 课后复习题：1、2、3、4、5、10 课后练习题：4、5、10、11 第九章竞争性市场分析 本章是核心知识点，几种模型的福利变化分析，包括图形、原理等必须理解、熟记。很可能会出大题或者是计算题，要能够计算福利变化。本章如果出计算题，难度也不会很大，在做题时要学会结合图形解题，这样比较清晰。 课后复习题：1、2、3、4、6、7、8、9 课后练习题：2、3、7、9、10、12、 第十章市场势力：垄断与买方垄断 本章除第七部分反托拉斯法之外都是重点内容，出题形式多为名词解释和计算。 课后复习题：1、2、3、6、7、8、9、10、11、12 课后练习题：4（典型题，垄断情况下征税）、6、8、9、11、12、15、18 第十一章有市场势力的定价 本章除搭售和广告之外都是重点内容，尤其是价格歧视部分，大题小题都有出现的可能，跨期价格歧视和两步消费制都是重要的概念。 课后复习题：1、3、5、8 课后练习题：5、9、17、 第十一章附录联合企业的内部转移定价 本章可以不看 第十二章垄断竞争和寡头垄断 除第7部分卡特尔之外，其余部分内容都比较重要。垄断竞争部分未出现过大题，寡头垄断中有三个重要的模型，古诺模型、斯塔克伯格模型、伯特兰模型，要很好的掌握。其中第6部分囚徒的困境对寡头定价的意义也较为重要。 课后复习题：1、4、5、6、7、8 课后练习题：2、3、4、5、6、11、 第十三章博弈论和竞争策略

平狄克第八版课后答案

平狄克第八版课后答案 【篇一：平狄克微观经济学课后习题答案-第7-8章】> 1.显性成本 2.她自己做其他事时会得到的最高收入 3.多用资本,少用工人 4.完全竞争价格给定,即斜率不变 5.不意味 6.意味着递增 7.avcac mc递增mc=avc最低点 mc=ac最低点 8.l形 9.长期扩展线为把等产量线簇上斜率相同点连起来,此时它改变了斜率 10.规模经济基础是内在经济,针对一种产品 范围经济基础是同时生产高度相关的产品. 练习题 1.avc=1000 ac=1000+1000/q 非常大,最后为1000 2.不对,除非工人只可以在这里找到工作 3.见书后 4.见书后 5.见书后 6.每个均衡点斜率更小 7不同意,应按不同时段定价,如不可,则同意 8.见书后 9.tc=120000+3000(q/40)+2000 ac=75+122000/q mc=75 ac随q减小 2个劳动组,1600元 1/4, 更大的生产能力 11.190万元 53元 53元 19元 第七章附录 练习题

1、我们考查规模报酬时可由f（ak，al）与af（k，l）之间的关系 判断 当f（ak，al）af（k，l）,表明是规模报酬递增； 当f（ak，al）=af（k，l）,表明是规模报酬不变； 当f（ak，al）af（k，l）,表明是规模报酬递减； （a）规模报酬递增；（b）规模报酬不变；（c）规模报酬递增。 2、根据已知条件，资本价格r=30，设劳动价格为w，则成本函数 c=30k+ wl 联立(1) ，(2)， (3)可得k=(w/3) 1/2 ,l=(300/w) 1/2 , 此时成本最小，代入成本函数c=30k+ wl，得c=2（300w）1/2 联立(1) ，(2)， (3)可得k/l=3/4 , 此时成本最小，即生产既定产出的成本最小化的资本和劳动的组合 为资本/劳动=3/4。 4、（a）已知q=10k0.8(l-40)0.2 , 得 mpl=2(k/ (l-40))0.8 , mpk=8( (l-40) / k)0.2 , 在最小成本点有： mpl/ mpk=w/r 即2(k/ (l-40))0.8/8( (l-40) / k)0.2=w/r， k/（l-40）=4 w/r ，l- 40=kr/4w， 0.80.20.2q=10k(l-40)=10 k（r/4w）， 最小需求为:k=q/10(r/4w)0.2，l=40+ q (r/4w)0.8/10 总成本函数为：tc=10q+kr+lw=10q+ q/10((4w)0.2r0.8+(r/4)0.8w0.2)+40w （b）当r=64，w=32时tc=10q+ (2*20.2+0.50.8)32 q/10+1280 tc=1280+10q+91.84 q/10=1280+19.184q 该技术呈现规模递减。 （c）当q=2000时，l=40+ q (r/4w)0.8/10≈155，即需要劳动力为：155/40=3.875 0.2k= q/10(r/4w)≈230，即需要机器为：230/40=5.75 产出边际成本为：19.184美元/件；平均成本为：（1280+19.184q）/q=19.824 美元/件。 22 第八章 复习题 1．厂商关闭的条件是pac,但当avcpac，厂商虽亏损，但不仅能 弥补全部的可变成本，尚可弥补部分的固定成本。

微观经济学总结(平狄克)

第一章绪论 经济学的两个主要分支：微观经济学和宏观经济学 微观经济学：经济学的分支，主要研究个体经济单位——消费者、厂商、工人和投资者的行为——以及由这些个体组成的市场本身的行为 微观经济学还特别关注经济个体之间怎样通过互动形成更大的经济单位——市场和行业 宏观经济学：经济学的分支，主要研究总量经济指标，诸如国民产出的水平和增长率、利率、失业以及通货膨胀 微观经济学是关于如何配置稀缺资源的学科 微观经济学的主题有权衡取舍、价格的作用和决定机制、市场的核心作用、理论和模型 实证分析：描述因果关系的分析（客观） 规范分析：解析“应该如何”一类问题的分析（主观） 市场：买方和卖方的集合，通过他们实际或潜在的相互作用来决定一种或多种商品的价格市场界定：确定一个具体的市场应包括哪些买者、卖者以及产品范围 套利：在一个地方低价买进，然后在另一个地方高价卖出的行为 完全竞争市场：有许多买者和卖者的市场，没有任何买者或卖者能够影响价格 市场价格：竞争性市场中通行的价格 市场范围：市场的边界，既包括地理的边界，又包括就产品范围而言的边界 名义价格：未经通货膨胀调整的绝对价格 实际价格：一种按照总体价格指标衡量的价格，就是通过膨胀调整后的价格 实际分析中，我们应该利用消费者价格指数或生产者价格指数把名义价格转换成实际价格消费者价格指数（Consumer Price Index, CPI）：衡量总体价格水平的指标 生产者价格指数(Producer Price Index, PPI)：衡量半成品和批发品的总体价格水平的指标 章节练习： 1、人们常说，一个好的理论是可以用实证的、数据导向的研究来加以证伪的。试解释为什

平狄克《微观经济学》(第9版)章节题库-第5章 不确定性与消费者行为【圣才出品】

第5章　不确定性与消费者行为 一、单项选择题 1．下列函数中，（ ）是可能来自一个风险偏好者的效用函数。 A．x1/2 B．lnx C．x2 D．ax 【答案】C 【解析】风险偏好者的预期效用函数是一个凸函数，即d2U/dx2＞0，只有C项符合这一特点。 2．假定某投资者面对两个投资项目A和B。项目A报酬为（x0＋h）的概率为1/2，报酬为（x0－h）的概率为1/2，h∈[0，x0]。项目B的报酬固定为x0。该投资者选择了项目B。那么，该投资者为（ ）。 A．风险厌恶者 B．风险偏好者 C．风险中性 D．不确定 【答案】A 【解析】由题意可知，（x0＋h）/2＋（x0－h）/2＝x0，即投资者投资项目A的期望值等于无风险条件下可以持有的固定报酬。投资者在这种前提下选择了项目B，表明他认

为无风险条件下持有固定财富的效用大于项目A的期望效用，因此是风险厌恶者。 3．假设你去买一张彩票，而且你知道将以0.1的概率得到2500元，0.9的概率得到100元。假设你的效用函数为U（w）＝w1/2，那么你从所购买的彩票中得到的期望效用为（ ）。 A．360 B．14 C．46 D．1300 【答案】B 【解析】期望效用的计算公式为 U（g）＝π1U（w1）＋π2U（w2） 其中，π1，π2为两种自然状态w1，w2发生的概率。将U（w）＝w1/2以及 π1＝0.1，w1＝2500，π2＝0.9，w2＝100代入期望效用计算公式，可得期望效用为14。 4．假设一个消费者的效用函数为U（w）＝w2，那么该消费者是（ ）。 A．风险规避的 B．风险中性的 C．风险偏好的 D．都不是 【答案】C 【解析】消费者的效用函数为U（w）＝w2，边际效用为MU（w）＝2w，边际效用

平狄克《微观经济学》(第7版)习题详解(第12章 垄断竞争和寡头竞争)

平狄克《微观经济学》（第7版） 第12章垄断竞争和寡头垄断 课后复习题详解 跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。 以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。 1．垄断竞争市场的特征是什么？在这样的一个市场中，如果一厂商推出一种新型的、改进的产品，对均衡价格和产量会产生什么影响？ 答：（1）垄断竞争市场的特征 垄断竞争市场指那种许多厂商出售相近但非同质，而是具有差别的商品的市场组织。一个垄断竞争的市场具有两个关键特征： ①集团中有大量的企业生产有差别的同种产品，这些产品彼此之间是非常接近的替代品。这些有差别的产品虽然是同一类产品，但在产品的商标、包装、设计、质量、性能、声誉、服务、销售渠道等方面具有差别。一方面，由于产品具有不同特色，因此不具有完全替代性；另一方面，又因为它们具有相似之处，从而具有高度的可替代性。 ②自由进出，即新厂商带着这种产品的新品牌进入市场和已有厂商在它们的产品已无利可图时退出都比较容易。 （2）对均衡价格和产量的影响 在一个市场中，如果一厂商推出一种新型的、改进的产品，会使得所有其它厂商的需求曲线向内移动，因此导致均衡价格和产量降低。 2．为什么在垄断竞争中厂商的需求曲线比总的市场需求曲线要平坦？假设一家垄断竞争厂商短期中有一个利润，长期中它的需求曲线会发生什么变化？ 答：（1）垄断竞争中厂商的需求曲线比总的市场需求曲线要平坦的原因 在垄断市场中，产品之间是非常接近的替代品，因而对某个品牌商品的需求弹性很大，所以厂商的向右下倾斜的需求曲线是比较平坦的，相对地比较接近完全竞争厂商的需求曲线的形状。而市场需求曲线表示的是消费者对某个生产集团所生产的一类产品的总的需求状况，这类产品对于消费者来说是必须的，替代品很少甚至没有，其需求弹性显然小于消费者对此类产品中不同品牌产品的需求弹性，因此市场需求曲线较单个厂商的需求曲线陡峭。 （2）长期中需求曲线会发生的变化 在短期内，垄断竞争厂商是在现有的生产规模下通过对产量和价格的同时调整，来实现 的均衡条件。在短期均衡时，垄断竞争性厂商可能获得最大的利润，也可能利润M R SM C 为零，也可能蒙受最小损失。而垄断竞争厂商在长期均衡时的利润必定为零，因为在垄断竞争市场上存在着相互竞争的厂商，其他厂商的进入将使得厂商的超额利润为零。 当生产集团内部某个厂商存在着利润时，新的厂商就会被吸引进来。当他们推出竞争性品牌时，在市场需求规模不变的条件下，这个厂商将会损失一部分市场份额，需求曲线、边际收益曲线向内平移，直至利润消失为止。

平狄克《微观经济学》(第8版)笔记和课后习题详解复习答案

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8.3课后练习题详解 第9章竞争性市场分析 9.1复习笔记 9.2课后复习题详解 9.3课后练习题详解 第3篇市场结构与竞争策略 第10章市场势力：垄断和买方垄断 10.1复习笔记 10.2课后复习题详解 10.3课后练习题详解 第11章有市场势力的定价 11.1复习笔记 11.2课后复习题详解 11.3课后练习题详解 第11章附录纵向联合厂商 第12章垄断竞争和寡头垄断 12.1复习笔记 12.2课后复习题详解 12.3课后练习题详解 第13章博弈论与竞争策略 13.1复习笔记 13.2课后复习题详解 13.3课后练习题详解 第14章投入要素市场 14.1复习笔记 14.2课后复习题详解 14.3课后练习题详解 第15章投资、时间与资本市场 15.1复习笔记 15.2课后复习题详解 15.3课后练习题详解 第4篇信息、市场失灵与政府的角色第16章一般均衡与经济效率 16.1复习笔记 16.2课后复习题详解 16.3课后练习题详解 第17章信息不对称的市场 17.1复习笔记 17.2课后复习题详解 17.3课后练习题详解 第18章外部性和公共物品 18.1复习笔记 18.2课后复习题详解

平狄克《微观经济学》(第8版)笔记和课后习题详解

第1篇导论：市场和价格 第1章绪论 1.1复习笔记 1．微观经济学的主题 （1）微观经济学的研究对象 微观经济学研究的是个体经济单位（如消费者、工人、投资者、土地所有者和企业）的行为，也研究构成市场与行业的消费者和厂商的相互影响。微观经济学的核心内容是论证亚当·斯密的“看不见的手”原理。 （2）经济模型 经济模型是现代经济理论的一种主要分析方法，也称为经济数学模型，指用数学形式所表述的经济过程或经济理论结构。现实世界的情况是由各种主要变量和次要变量构成的，因而非常复杂，只有把次要因素排除在外，才能对经济运行进行严格的分析。运用经济模型，事先做出某些假设，可以排除掉许多次要因素，从而建立起一定的模型，然后通过运用这一模型，可以对错综复杂的现实世界做出简单的描述。 （3）经济理论的局限性 在经济学、物理学或者其他学科中，没有一个理论是绝对正确的。理论的有用性和合理性取决于它是否对其试图解释和预测的一系列现象成功地做出了解释和预测。比如说，厂商并不总是追求其利润的最大化的，因此，厂商理论只在解释厂商某些行为（如资本投资决策的时机）时才获得了有限的成功。尽管如此，这一理论确实解释了有关厂商和行业的行为、成长和演变方面的大量现象，所以它已经成为决策者手中一个重要的工具。 2．实证分析和规范分析 （1）微观经济学的分析方法 微观经济学既研究实证问题，也研究规范问题。实证问题主要是解释和预测，规范问题则研究“应该如何”。实证分析和规范分析都是重要的经济学分析方法。 （2）实证分析和规范分析的含义 实证分析是进行经济分析的一种重要方法，特点是它对有关命题的逻辑分析，旨在理解经济过程实际是什么、将会是什么、为什么，而不涉及对结果好坏和是否公平的评价，其中不包含任何价值判断。实证分析既有定性分析，也有定量分析。 规范分析也是经济学分析经济问题的一种方法，它以一定的价值判断作为出发点，提出行为的标准，并研究如何才能符合这些标准。它力求说明“应该是什么”的问题，或者说，它回答这样的问题：为什么要做出这种选择，而不做出另一种选择？ （3）实证分析和规范分析的关系 实证分析和规范分析既有联系又有区别。规范分析和实证分析的区别可归纳为以下三点： ①规范分析在研究经济事物的同时树立一个判别标准，以便能对分析结果做出好与坏的判断；而实证分析则只对经济运行过程本身做出描述，并不做出好与坏的判断。 ②二者要解决的问题不同。规范分析要说明经济事物是否符合既定的价值标准；实证分析则要解决经济“是什么”的问题，要研究经济变量的规律及其相互之间的联系，并对未来做出预测。 ③规范分析没有客观性，其结论受到价值标准的影响；实证分析的内容具有客观性，其结论可以接受事实的验证。 尽管有上述区别，实证分析和规范分析二者之间仍相互联系:：规范分析以实证分析为基础，而实证分析则以规范分析为指导;实证分析的结果往往要以一定的价值判断作为最终目标，而规范分析的结论往往又是实证分析的出发点。 3．微观经济学的核心 微观经济学的核心是价格分析。微观经济学对单个经济单位的考察，是在三个逐步深入的层次上进行的，而这三个层次都与价格因素有关： 第一个层次是分析单个消费者和单个生产者的经济行为，它分析单个消费者如何进行最优的消费决策以获得最大的效用以及单个生产者如何进行最优的生产决策以获得最大的利润，这里面都涉及到了价格问题。 第二个层次是分析单个市场的价格决定问题。这种单个市场的价格决定，是作为单个市场中所有的消费者和所有的生产者的最优经济行为共同作用的结果而出现的。应该说，在第二个层次中，价格是核心。 第三个层次是分析所有单个市场的价格的同时决定。这种决定是作为所有单个市场相互作用的结果而出现

平狄克《微观经济学》(第8版)配套题库(下册)-课后习题-一般均衡与经济效率【圣才出品】

第16章一般均衡与经济效率 16.1课后复习题详解 1．为什么反馈效应能使一般均衡分析与局部均衡分析存在很大的不同？ 答：可以通过一个例子来分析反馈效应能使一般均衡分析与局部均衡分析发生很大的差异的原因。考察录像带租赁和影剧院门票这两个竞争市场。这两个市场有紧密的联系，是因为录像机的普遍拥有使大多数顾客可以选择在家而不是去影剧院看电影。影响某一市场的价格政策变动也会影响另一个市场，而该市场的变化又会对第一个市场产生反馈效应。现在假定政府对购买每一张电影票征收1美元的税。这一税收的局部均衡效应就是使对电影的需求曲线向上提高1美元。电影税会影响录像市场是因为电影和录像是替代品。局部均衡分析会低估税收对电影票价格的影响。录像市场受到影响后，又通过反馈效应影响电影票价格，结果必然同时决定电影和录像两者的均衡价格和均衡数量。 2．解释埃奇沃思盒形图中的一点是如何同时代表两个消费者所拥有的商品配置的。 答：假定两种产品分别为X和Y，其既定数量为X′和Y′，两个消费者分别为A和B，如图16-1所示的埃奇沃思盒形图，盒子的水平长度表示整个经济中的第一种产品X的消费量X′，盒子的垂直长度表示第二种产品Y的数量Y′，O A表示第一个消费者A的原点，O B 表示第二个消费者B的原点，从O A水平向右测量消费者A对第一种商品X的消费量X A，垂直向上测量它对第二种商品Y的消费量Y A；从O B水平向左测量消费者B对第一种商品X 的消费量X B，垂直向下测量消费者B对第二种商品Y的消费量Y B。现在考虑盒中的任意一点D，对应于消费者A的消费量（X a，Y a）和消费者B的消费量（X b，Y b），这样，X a＋X b

平狄克微观经济学课后习题答案(中文)

平狄克微观经济学课后习题答案(中文)

第一章 复习题 1．市场是通过相互作用决定一种或一系列产品价格的买卖双方的集合，因此可以把市场看作决定价格的场所。行业是出售相同的或紧密相关的产品的厂商的集合，一个市场可以包括许多行业。 2．评价一个理论有两个步骤：首先，需要检验这个理论假设的合理性；第二，把该理论的预测和事实相比较以此来验证它。如果一个理论无法被检验的话，它将不会被接受。因此，它对我们理解现实情况没有任何帮助。 3．实证分析解释“是什么”的问题，而规范分析解释的是“应该是什么”的问题。对供给的限制将改变市场的均衡。A中包括两种分析，批评这是一种“失败的政策”——是规范分析，批评其破坏了市场的竞争性——是实证分析。B向我们说明在燃油的配给制下总社会福利的被损坏——是实证分析。 4．由于两个市场在空间上是分离的，商品在两地间的运输是套利实现的条件。如果运输成本为零，则可以在Oklahoma购买汽油，到New Jersey出售，赚取差价；如果这个差价无法弥补运输成本则不存在套利机会。 5．商品和服务的数量与价格由供求关系决定。鸡蛋的实际价格从1970年至1985年的下降，一方面是由于人们健康意识的提高而导致鸡蛋需求的减少，同时也因为生产成本的降低。在这两种因素下，鸡蛋的价格下降了。大学教育的实际价格的升高，是由于越来越多的人倾向于获得大学教育而导致需求提高，同时教育的成本也在升高。在这两方面因素作用下，大学教育费用提高了。 6．日圆相对美圆来说，价值升高，升值前相比，兑换同样数量的日圆需要付出更多的美圆。由汇率的变化引起购买力的变化，在日本市场出售的美国汽车，由于美圆贬值日圆升值，持有日圆的消费者将较以前支付较底的价格；而在美国市场出售的日本汽车，由于日圆升值美圆贬值，持有美圆的消费者将面对较以前提高的价格。

平狄克《微观经济学》(第7版)课后习题详解 第8章~第9章【圣才出品】

第8章利润最大化和竞争性供给 8.1课后复习题详解 1．为什么一个发生亏损的厂商选择继续进行生产而不是关闭？ 答：一个发生亏损的厂商选择继续进行生产而不是关闭的原因在于：此时的价格仍然大于平均可变成本，但小于平均成本。具体来讲： （1）厂商发生亏损是指总收益TR小于总成本TC，此时，如果总收益TR仍然大于可变成本VC，厂商继续生产将会弥补VC，并且可以弥补一部分的固定成本FC，弥补量是 ，从而使损失最小化，因此在短期内，厂商不会关闭而是继续生产。 TR VC （2）停止营业点是指一个已经投入生产的企业，在生产中总有这样一点，当根据利润最大化原则确定的产量大于这一点所代表的产量时，仍可以继续生产，小于这一点所代表的产量时，就只好关闭。 一个已经投入生产的企业是否必须关闭的条件不在于它是否盈利，而在于它关闭后的亏损与生产时的亏损哪种情况更大。如果关闭后的亏损比生产时的亏损更大，则应继续生产；如果生产时的亏损比关闭后的亏损更大，则必须关闭。实际上关闭后也是有亏损的，其亏损就是固定成本。因此，是否关闭就视生产时的亏损是否大于固定成本而定，若不大于，就可继续生产，若大于，就必须停止营业。企业的停止营业点可用图8-1说明：图中N点即平均可变成本最低点就是企业停止营业点。

图8-1停止营业点 （3）当市场决定的价格为 P时，均衡产量为2Y，恰好等于N点所表示的产量。这时， 2 总亏损为面积BFJN，即等于总固定成本。此时，厂商的平均收益AR等于平均可变成本AVC，厂商可以继续生产，也可以不生产，也就是说，厂商生产或不生产的结果都是一样的。这是因为，如果厂商生产的话，则全部收益只能弥补全部的可变成本，不变成本得不到任何弥补。如果厂商不生产的话，厂商虽然不必支付可变成本，但是全部不变成本仍然存在。由于在这一均衡点上，厂商处于关闭企业的临界点，所以，该均衡点也被称作停止营业点或关闭点。 2．解释为什么行业长期供给曲线不是行业长期边际成本曲线。 答：（1）供给曲线是指每一可能的价格下厂商将生产的产量。供给曲线有短期和长期之分。 （2）在完全竞争条件下，单个厂商是价格接受者。在短期，企业生产规模固定不变，厂商通过选择产量水平以实现利润最大化。厂商将增加产量直到价格等于边际成本，但如果价格低于平均可变成本，它则会不生产。因此一个厂商的短期供给曲线是短期边际成本曲线（位于最小平均可变成本点之上的部分）。

平狄克微观经济学读后感想

专业名著阅读通识课读后感 微观经济学

经济、经济学是一个和奇妙而奇特的东西，因为在经济领域中充满了太多的不确定因素、偶然因素。就拿房价来说，众多的经济学家预测房价不会涨，房价只能逐渐下降，可事实上，各地房价并没有呈现下降趋势，而是稳重有升为主流。就连二手房也是以升值为主。但是并不能因此说哪些经济学家是所谓的“经济家”。因为市场、经济、经济学这个大环境中充满了很多不可控、偶然因素。 我想，学习微观经济学也并不一定是要要求我们学会多少知识，一定要准确的预测、估计未来的经济态势怎样，而是让我们能以一个视角以去感知这变化多端、复杂奥妙的世界。让我们能够灵活的在这个大经济市场中去感知、去收获、去成长。 大三上学期，我拜读了罗伯特?平狄克的微观经济学。不得不说，这本书是一本非常经典的微观经济学教材。首先说一下全书的基本结构，全书分为四个大的篇章。第一篇为绪论、供给和需求的基本原理。第二篇为消费者行为、个人需求和市场需求、不确定性和消费者行为、生产、生产成本、利润最大化和竞争性供给、竞争性市场分析。第三篇为市场势力：垄断与买方垄断、有市场势力的定价、垄断竞争和寡头竞争、博弈论和竞争策略、投入要素市场、投资与时间及资本市场。第四篇为一本均衡和经济效率、信息不对称市场、外部性与公共品等内容。 第一次学习，我对全书的概念做了一个基本性的学习。这本书概念十分详尽，包括供求理论、消费理论、生产和成本理论、厂商价格、产量决策理论、市场失灵、政府干预理论。还有最近几年兴起的博弈论、信息不对称、环境污染之类的外部性问题等。 比如固定陈本：无论产出水平如何都不会变化的那部分成本；只有企业退出生产，这部分成本才不会发生。 可变成本：随产量不同而发生变化的那部分成本。 沉淀成本：已经发生而无法收回的支出。 以例子来更好的说明像我们身边的比萨店。对于比萨店来说，成本中最大的一部分是固定成本，二沉淀成本非常低，因为如果退出，比萨烤炉、椅子、桌子、碟子都可以转手。可变成本也十分低，主要是制作比萨的各种原料（面粉、番茄酱、奶酪、香肠等）和帮助制作、传送比萨的工人的工资。大多数成本是固定成

平狄克《微观经济学》(第8版)配套题库(下册)-课后习题-博弈论与竞争策略【圣才出品】

第13章博弈论与竞争策略 13.1课后复习题详解 1．合作博弈和非合作博弈之间的区别是什么？各举出一个例子。 答：博弈按照参与人之间能否达成协议分为合作博弈与非合作博弈。能达成协议的称为合作博弈，合作博弈强调团队理性；不能达成协议的称为非合作博弈，非合作博弈更注重个人理性。 合作博弈和非合作博弈之间的主要差别是一份有约束力的合同，即双方必须坚持的一项协议，在合作博弈中是可能的，但在非合作博弈中是不可能的。合作博弈的一个例子是关于一个行业中的两个厂商谈判一项开发一种新技术的联合投资（假设其中任何一个厂商都没有能独自成功的足够知识）。如果两个厂商能够签订一份分配联合投资利润的有约束力的合同，则使双方都获益的合作的结果就是可能的。非合作博弈的一个例子就是两竞争的厂商相互考虑到对方的可能的行为，并独立确定价格或广告策略以夺取市场份额的情况。 2．什么是占优策略？为什么一个占优策略均衡是稳定的？ 答：占优策略指不管其对手采取什么策略，该竞争者采取的策略都是最优策略。占优策略均衡是指博弈方都采用占优策略所达到的均衡。占优策略均衡是一种纳什均衡。纳什均衡指每一个竞争者都确信，在给定竞争对手策略决定的情况下，他选择了最好的策略。占优策略均衡稳定的原因是参与者在均衡时都没有激励去改变各自的策略。 3．解释纳什均衡的含义。它与占优策略均衡有何不同？

答：（1）纳什均衡的含义 纳什均衡指这样一种策略集，在这一策略集中，每一个博弈者都确信，在给定竞争对手策略决定的情况下，他选择了最好的策略。纳什均衡是由所有参与人的最优策略所组成的一个策略组合，也就是说，给定其他人的策略，任何个人都没有积极性去选择其他策略，从而没有人有积极性去打破这个均衡。 （2）纳什均衡和占优策略均衡的不同 占优策略的均衡是纳什均衡的一种特例，不管其他博弈方如何做，占优策略总是最优的。纳什均衡依赖各博弈方的理性。 占优策略均衡：我所做的是不管你做什么我所能做的最好的；你所做的是不管我做什么你所能做的最好的。 纳什均衡：我所做的是给定你所做的我所能做的最好的；你所做的是给定我所做的你所能做的最好的。 4．一个纳什均衡与一个博弈的极大化极小解有什么区别？在什么样的情况下，一个极大化极小解是比纳什均衡更可能的结果？ 答：（1）极大化极小策略是博弈中的一种策略，即选择所有最小可能收益中的最大值。与纳什均衡不同，极大化极小策略的解决办法不要求各博弈方对其对手的选择有反应。如果没有有势力的策略存在（在这种情况下结果取决于对手的行为），各博弈方能通过适当的极大化极小策略降低依赖于其对手理性的固有的不确定性。 （2）如果非理性的行为发生的可能性很高或者如果对手非理性将会造成巨大损失，极大化极小解的解决办法比纳什均衡解更可能。

平狄克《微观经济学》(第7版)习题详解(第2章 供给和需求的基本原理)

平狄克《微观经济学》（第7版） 第2章 供给和需求的基本原理 课后复习题详解 跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。 以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。 1．假定异常炎热的天气会使冰淇淋的需求曲线向右移动，解释为什么冰淇淋价格会上升到一个新的市场出清水平。 答：如图2-3所示，假设短期内供给完全无弹性，则供给曲线是垂直的。供给曲线S 与初始的需求曲线1D 相交，确定均衡价格为1P ，均衡数量为1Q 。异常炎热的天气会使冰淇淋 的需求曲线向右移动，在当前价格1P 上造成短期需求过剩，消费者为获得冰淇淋，愿意为每 一单位冰淇淋出价更高。在需求压力下，冰淇淋价格将上升，直到供给与需求达到均衡。 图2-3 冰淇淋的供求分析 2．请运用供给曲线和需求曲线来说明以下各事件会怎样影响黄油的价格、销售量及购买量： （1）人造黄油价格上升； （2）牛奶价格上升； （3）平均收入水平下降。 答：（1）人造黄油和黄油是一对替代品。人造黄油价格上升将导致黄油消费量的上升，因此黄油的需求曲线将从1D 向右移动至2D ，均衡价格将从1P 上升至2P ，均衡数量将从1Q 增加至2Q ，如图2-4所示。

图2-4 人造黄油价格上升的影响 （2）牛奶是黄油的主要原料。牛奶价格上升将增加黄油制造成本。黄油的供给曲线将从1S 向左移动至2S ，在更高的价格2P 实现均衡，同时供给量减少到2Q ，如图2-5所示。 图2-5 牛奶价格上升的影响 （3）假设黄油是正常商品。平均收入水平下降将导致需求曲线从1D 向左移动至2D ，结果价格降至2P ，需求量也下降至2Q ，如图2-6所示。 图2-6 平均收入下降的影响 3．如果玉米片价格上升3%而使其需求量下降6%，那么玉米片的需求价格弹性是多少？ 解：需求价格弹性指某种商品需求量变化的百分率与价格变化的百分率之比，它用来测度商品需求量变动对于商品自身价格变动反应的敏感性程度。 所以，玉米片的需求价格弹性是：623D P Q E P %?-%===-%?% 。在这里，需求价格弹性的绝对值大于1，表明它在需求曲线的富有弹性区域。

微观经济学重要名词概念解释-平狄克版

微观经济学重要名词概念解释 1、市场的范围：指市场的边界，既包括地理的边界，又包括就产品范围而言的边界。 2、名义价格：就是它的绝对价格，有时也被称为“现值美元”价格。 3、实际价格：又称“不变美元”价格，是经过通胀调整后的价格。 4、供给曲线：表示在其他影响某商品供给的因素不变情况下，对应于每一给定的价格，生产者所愿意生产的该商品的数量。 5、需求曲线：表示在每一给定的价格水平上，消费者所愿意购买的某种商品的数量。 6、均衡：供给与需求曲线交点处的价格与数量即为均衡或市场出清价格与数量。 7、市场机制：一个自由市场里，价格会不断变化直到市场出清为止的趋势。 8、需求价格弹性：价格每变动1%，该商品的需求量将会发生多大百分比变化，度量需求量对于价格变化的敏感性。 9、供给价格弹性：价格每变动1%，该商品的供给量将会发生多大百分比变化，度量供给量对于价格变化的敏感性。 10、需求收入弹性：收入每增加1%引起的需求变动。 11、需求的交叉价格弹性：因一种商品价格增加1%所引起的另一种商品需求量的百分比变化。 12、收入弹性：对绝大多数商品和劳务来说，需求收入弹性长期大于短期，而对一些耐用品来说，如汽车，短期要大于长期。 13、周期性行业：销售量波动会放大国内生产总值（GDP）与国民收入波动的周期性变化的行业。 14、有关偏好的一些基本假设：1、完备性。2、可传递性。3、越多越好（课本P66） 15、无差异曲线：同一条代表了能带给消费者相同满足程度的所有市场篮子组合。 16、无差异曲线簇：一组无差异曲线。 17、边际替代率：消费者为获得一单位某种商品而愿意的放弃的另一种商品的最大数量。 18、完全替代品：边际替代率为常数的两种商品。 19、完全互补品：边际替代率为0或无穷大，并且无差异曲线为直角形状的两种商品。 20、厌恶品：消费者认为不好的东西，少一点比多一点好，比如空气污染。 21、效用：对消费者从一个给定的市场篮子中得到满足程度的数值表示。 22、效用函数：赋予每个市场篮子以一定效用水平的方程。 23、效用可能性边界：用两人的效用水平来衡量所有有效的资源配置曲线。 24、序数效用函数：能产生对市场篮子排序的效用函数。 25、基数效用函数：能描述一个市场篮子在多大程度上臂另一个更受偏好的效用函数。

平狄克微观经济学 名词解释

第一章绪论 1、实证分析 实证经济学回答了“是什么”的问题，研究实际经济体系是怎样运行的，它对经济行为做出有关假设，根据假设分析和陈述经济行为及其后果，并试图对结论进行检验。旨在理解经济过程实际是什么、将会是什么、为什么，不涉及对结果好坏和是否公平的评价，不包含任何价值判断。 2、规范分析 规范经济学回答了“应当是什么”的问题，从一定的社会价值判断标准出发，根据这些标准，对一个经济体系的运行进行评价，并进一步说明一个经济体系应当怎样运行，提出相应的经济政策。 实证分析和规范分析的区别： （1）价值判断——规范分析设立评判标准，对结果好坏做出判断；实证分析只描述经济运行过程，不做出好坏的判断。 （2）解决的问题不同——规范分析说明经济事物是否符合既定的价值标准；实证分析研究“是什么” （3）是否具有客观性——规范分析没有客观性，结论受价值判断影响；实证分析有客观性。联系：规范分析以实证分析为基础，实证分析以规范分析为指导；实证分析的结果以一定的价值判断为最终目的，规范分析的结论是实证分析的出发点。 3、经济学分析方法 静态分析：考察在既定的条件下某一经济事物在经济变量的相互作用下所实现的均衡状态。例：均衡价格决定模型。 比较静态分析：考察当原有条件或外生变量发生变化时，原有的均衡状态会发生什么变化，并分析比较新旧均衡的位臵。例：均衡价格决定模型，外生变量变化引起供给或需求曲线移动。 动态分析：在引进时间变化序列的基础上，研究不同时点上变量相互作用在均衡状态的形成和变化过程中所起的作用，考察在时间变化过程中均衡状态的实际变化过程。例：蛛网模型。 第二章供给和需求的基本原理 1、弹性 （1）需求价格弹性：商品需求量变化的百分率与价格变化的百分率之比，表示在一定时期商品价格变化百分之一时引起该商品需求变化的百分比。 决定因素：需求曲线斜率、价格、数量。 需求价格弹性沿曲线变化。

平狄克微观经济学答案[微观经济学模拟试题三答案]

平狄克微观经济学答案[微观经济学模拟试题三答案] 《经济学》模拟试卷三 一、选择题（每题1.5分，共计39分） (1)需求量与需求的变动: D A. 不一样 B.一样 C.都由同一原因引起 D. 需求量的变动仅受价格影响，需求变动由除价格之外的其它因素引起 （2）在得出某消费者的纯棉衬衫需求曲线时，下列因素中，除哪项因素以外，其余保持不变： C A. 麻衬衫的价格 B.收入水平 C.纯棉衬衫的价格 D.纯棉衬衫的广告宣传 （3）对于一种商品，消费者想要有的数量都已有了，这时： B A. 边际效用最大Ｂ．边际效用为零； C ．总效用为零 D ．都不对

（4）如果消费者消费的x 、y 商品的价格之比是1.25，它们的 边际效用之比是2，为达到效用最大化，消费者应： A A ．增购x 和减少购买y B ．增购y 和减少购买x C ．同时增购x 、y 两种商品 D ．同时减少x 、y 的购买量 （5）以下说法正确的是： C A. 只要边际产量减少，平均产量就减少 B. 只要边际产量减少，总产量就减少 C. 只要总产量减少，边际产量就一定为负 D. 只要平均产量减少，总产量就减少 （6）规模收益递减可能是在下述哪种情况下发生的： A A. 按比例连续增加各种生产要素 B不按比例连续增加各种生产 要素 C. 连续地投入某种生产要素而保持其他生产要素不变

D. 不投入某种生产要素而增加其余生产要素的投入 （7）已知某企业的生产函数为Q L K ，则该企业生产处于： B A. 规模收益递增阶段 B. 规模收益不变阶段 C. 规模收益递减阶段 D. 边际收益递减阶段 （8）在长期中，下列成本哪一项是不存在的： A A．固定成本 B．平均成本 C．机会成本 D．隐性成本 （9）在短期生产中，当边际产量达到最大值时，下列哪项成本达到最小值： C A ．平均成本 B．边际成本 C．平均可变成本 D．平均不变成本 （10）如果一个企业经历规模收益递增阶段，则LAC 曲线是： B A ．上升的 B．下降的 C．垂直的 D．水平的