8. A case study in the chapter describes a phone conversationbetween the presidents of American Airlines and Braniff Airways.Let’s analyze the game
between the two companies. Suppose that each company can chargeeither a high price for tickets or a low price. If one companycharges $100, it earns low
profits if the other company charges $100 also, and high profits ifthe other company charges $200. On the other hand, if the companycharges $200, it earns very low profits if the other companycharges $100, and medium profits if the other company charges $200also.
a. Draw the decision box for this game. 画出这个博弈的决策方框答：
| 布拉妮弗航空公司决策 |
低票价 | 高票价 |
美洲航空公司决策 | 低票价 | 布拉妮弗利润：低 美洲利润：低 | 布拉妮弗利润：非常低 美洲利润：高 |
高票价 | 布拉妮弗利润：高 美洲利润：非常低 | 布拉妮弗利润：中等 美洲利润：中等 |
b. What is the Nash equilibrium in this game?Explain.这场博弈的纳什平衡是什么？
答：对两家航空公司而言，优势策略都是低票价。纳什均衡就是两家航空公司都实行低价策略。
c. Is there an outcome that would be better than the Nashequilibrium for both airlines? How could it be achieved? Who wouldlose if it were achieved?有无一种结局比纳什平衡对两家航空公司都更好？如何达成这个结局？如果达成这种结局，谁受损失？
答：两家航空公司都实行高票价，需要两家公司串通。乘客受损失。
9. Farmer Jones and Farmer Smith graze their cattle on the samefield. If there are 20 cows grazing in the field, each cow produces$4,000 of milk over its
lifetime. If there are more cows in the field, then each cow caneat less grass, and its milk production falls. With 30 cows on thefield, each produces $3,000 of milk; with 40 cows, each produces$2,000 of milk. Cows cost $1,000 apiece.
a. Assume that Farmer Jones and Farmer Smith can each purchaseeither 10 or 20 cows, but that neither knows how many the other isbuying when she makes her purchase. Calculate the payoffs of eachoutcome.计算每种结局的获利。
答：
| 约翰决策 |
10 头牛 | 20 头牛 |
斯密斯决策 | 10 头牛 | 约翰获利：$30,000 斯密斯获利：$30,000 | 约翰获利：$40,000 斯密斯获利：$20,000 |
20 头牛 | 约翰获利：$20,000 斯密斯获利：$40,000 | 约翰获利：$20,000 斯密斯获利：$20,000 |
b. What is the likely outcome of this game? What would be thebest outcome? Explain.这个博弈可能的结局是什么？最好的结局是什么？
答：约翰和斯密斯的优势策略都是养20头牛。所以可能的结果就是每人养20头牛，每人获利20，000元。最好的结果是每人养10头牛，各获利30，000元。
c. There used to be more common fields than there are today. Why?(For more discussion of this topic, reread Chapter11.)以前这种公用地要比现在多，为何？
答：公用地容易造成过度使用，所以公用地被逐步私有化了。
10. Little Kona is a small coffee company that is consideringentering a market dominated by Big Brew. Each company’s profitdepends on whether Little Kona
enters and whether Big Brew sets a high price or a low price:
Big Brew threatens Little Kona by saying, “If you enter, we’regoing to set a low price, so you had better stay out.” Do you thinkLittle Kona should believe the threat? Why or why not? What do youthink Little Kona should do?
答：不应该理会大布瑞德威胁。如果大布瑞采用低价策略，他自己将会遭受2百万损失，他肯定不会这样做。
11. Jeff and Steve are playing tennis. Every point comes down towhether Steve guesses correctly whether Jeff will hit the ball toSteve’s left or right. The
outcomes are:
Does either player have a dominant strategy? If Jeff chooses aparticular strategy (Left or Right) and sticks with it, what willSteve do? So, can you think of a better strategy for Jeff tofollow?
答：这是随机事件。不存在优势策略。
