跪求这道题的答案~急

咱想要详细的过程，因为是要交的
大家别怪咱这样作弊，实在因为老师用英文上课听不懂，而上课的都是大三的师兄师姐，他们都是学过高级微观课的，老师都讲给他们听啊，我刚过完大一，悔只在我选错课...
听说这个版高手多，大家麻烦下...
咱就这么多钱了，拜托各位高人了，学分绩啊~~~~
下面是从PDF直接复制来的，看不方便的话麻烦下载帖子下面的"homework 3.pdf"，或者这里给纳米盘下载链接：http://d.namipan.com/d/b67b943c0ec4f92b394d3b8ae00d56defdb6daacf2600000

Homework III
1. Consider a market for loans to finance investment projects. All investment
projects require an outlay of 1 dollar. There are two types of projects: good
and bad. A good projects has a probability of pG of yielding profits of  > 0
and a probability (1 − pG) of yielding profits of zero. For a bad project, the
relative probabilities are pB and (1 − pB), respectively, where pG > pB. The
fraction of projects that are good is  2 (0, 1).
Entrepreneurs go to banks to borrow the cash to make the initial outlay
(assume for now that they borrow the entire amount). A loan contract specifies
an amount R that is supposed to be repaid to the bank. Entrepreneurs
know the type of project they have, but the banks do not. In the event that
a project yields profits of zero, the entrepreneur default on her loan contract,
and the bank receives nothing. Banks are competitive and risk neutral. The
risk-free rate of interest (the rate the banks pay to borrow funds) is r. Assume
that
pG − (1 + r) > 0 > pB − (1 + r).
(a) Find the equilibrium level of R and the set of projects financed. How
does this depend on pG, pB, , , and r?
(b) Now suppose that the entrepreneur can off to contribute some fraction
x of the 1 dollar initial outlay from her own funds (x 2 [0, 1]). The
entrepreneur is liquidity constrained, however, so that the effective cost
of doing so is (1 + )x, where  > r.
(i) What is an entrepreneur’s payoff as a function of her project type,
her loan-repayment amount R, and her contribution x?
(ii) Describe the best (from a welfare perspective) separating perfect
Bayesian equilibrium of a game in which the entrepreneur first
makes an offer that specifies the level of x she is willing to put
into a project, banks then respond by making offers specifying the
level of R they would require, and finally the entrepreneur accepts
a bank’s offer or decides not to go ahead with the project. How
1
does the amount contributed by entrepreneurs with good projects
change with small changes in pB, pG, , , and r?
(iii) How do the two types of entrepreneurs do in the separating equilibrium
of (b) (ii) compared with the equilibrium in (a)?

这个问题不是很简单的计算嘛！哪需要什么高微啊！
（1）第一个问题的解决方法宗旨是：银行投资企业家项目比投资无风险项目获取的利润高。这里没有沉没成本的概念，投资失败本金也能收回。
所以：λ*PG*R+(1-λ)*PB*R>r，这里不需要考虑企业家的收益，因为他是空手套白狼，只要有收益一定会上的。
对于银行来说：R>r /[ λ*PG+(1-λ)*PB]，满足这个条件，银行就投资。至于各个因素对于这个公式的影响，自己看方程傻子都能解了。

？？？？？？？？？？？？？？？

2# hxl123456

就是一道题目咯，好像是委托代理问题~下那个PDF文件就明白咯~

没人帮忙吗？自己顶起~明天就要交咯~咱连题目都不太懂....555555555555

2# hxl123456 w

我算是搞明白了~其实就是张维迎那本博弈论与信息经济学后面的一道题，就是那道银行给两个高风险和低风险的项目贷款，贷1美元的那道~谁帮忙解一下啊~这本书都找不到答案~论坛上流传的那份600多K的答案里没有这道题~急啊

中文版翻译：

http://www.pinggu.org/bbs/viewthread.php?tid=499931&extra=

（mas-colell,whinston and green 1995）考虑项目融资的信贷问题。假定有两类投资项目，好项目和坏项目，每个项目需要1美元的投资，有两种可能的结果，成功（收益为Π>0）或失败（收益等于零）；好项目成功的概率为PG，坏项目成功的概率为PB，PG>PB。好项目的比例为λ。
假定企业家没有自有资金，因此全部投资都要从银行借。信贷合同规定，每元贷款的偿还数额为R（<Π）（包括利息和本金）。企业家知道项目的质量，银行不知道。如果项目成功，银行得到R，企业家的到Π-R；如果项目不成功，企业家违约，银行的收入为零。假定银行是竞争性的，并具有风险中性编号。无风险的利率为r。假定下列条件成立：
PG*Π-（1+r）>0>PB*Π-（1+r）
（即好项目值得进行，坏项目不值得进行）
（1） 求均衡还款额R和均衡投资的项目的集合；均衡如何依赖于PG,PB, λ，Π，r
（2） 现在假定企业家可以自己拿出x比例的钱投资（x属于0到1）。但因为流动性约束的限制（如企业家必须将一些很值钱的东西以较低的价格换成现金），这样做的实际成本是（1+ρ）x，ρ>r。
①． 求企业家的收入和其项目类型，还款额R和自投资金比例x之间的函数关系
②． 假定企业家首先决定自投资金比例x，银行根据x决定是否满足企业家的贷款要求及偿还额R，企业家再决定是接受银行的条件还是放弃项目。什么试“最好的”（从福利角度看）分离均衡？具有好项目的企业家的自投资金比例如何随PG,PB, λ，Π，r而变化
③． 与（1）的均衡相比，②的均衡中两类企业家的行为如何不同

太恐怖了吧

niu B还真看不懂，看懂了也不会解
高微的题～

好强悍。。。

呵呵，强啊