以下是引用我爱金融在2008-10-5 15:49:00的发言:1.Mr. F. Slob (risk neutral) is thinking of joining a gym. He does not know whether he will have the resolve to frequent the gym once he has paid the membership fee. He could (i) do nothing, (ii) join now for a year and pay £400 membership fee, or (iii) opt for a £50 one month trial membership and decide at the end of the month whether to join for the rest of the year for an additional £400. If he turns out to like the gym, which happens with probability p, his benefit from membership is £800.
(a) 1.Draw a decision tree and find the optimal decision for all p
(b) Graph the EVPI as a function of p.(EVPI是什么?)
2.Toby is indifferent between $7 for sure and a lottery with a 50% chance of payoff
zero and a 50% chance of payoff $20.
(a) Show that this is consistent with Toby’s utility of money function U(x)=1-ax
where a=0.93807.
(b) Show that Toby prefers $1 for sure to a lottery with a chance p of payoff Z and
1-p of payoff zero, for any positive Z, if p<0.06.
关键这两个题目都不好写。
第一个题目,根据题意,建立方程
[p×(800-400)+(1-p)×(-400)]=0
p×(800-450)+(1-p)×(-50)=[p×(800-400)+(1-p)×(-400)]
然后算出两个p,就是变换选择的节点了。
很显然第一个是0.5,第二个是0.875
第二个题目的思路类似,你先试试看吧,如果不行,就翻译成中文,我才敢做。
呵呵,看球去。
