求助一道Corporate Finance题，谢谢 first, 谢谢, called, False, style

600397374

Copper was first discovered in 1870 in a town called Cobar. BPH resources currently own an unused copper mine in Cobar that was shut down four years ago due to the depressed price of copper. However, due to the recent resources boom, BPH are considering re-opening the mine.

Company management forecast that it would cost $100,000 to re-open the mine and they would extract 100,000 pounds of copper per year for three years if the mine was re-opened. After that time the deposit will be exhausted.  The current copper price is $4 per pound and it costs $3.60 per pound to extract. Each year the price is equally likely to rise or fall by $0.50 from its level at the start of the year. Assuming a discount rate of 10% should BPH open the mine now or should they wait one year to see if the price of copper rises?

求助各位前辈，对这道题应该按照什么思路做？

zyp444

In my opinion, maybe it's a way to think from the perspective of option: if open now, Company forcast the cashflow and NPV based on the price of $4; if wait for one year, then Company get a one-year option, which means either open or not open one year later, based on the price then.

Cody2008

这道题目感觉就是一个概率题目吧，因为(4.0+0.5)/4 > 10% 所以如果在价格上涨的情况下再开copper mine肯定是比现在收益多一些。

但是问题是这个也只有0.5的概率发生。题目没有说清楚是否在价格下跌的情况下认为是潜在的损失。

楼主可否明示一下答案的分析？

[em01]

mestead

既然折现率已经给定了 就好做了 直接把未来现金流折现,求出净现值 就可以决定了

其实价格的不确定性已经在给定折现率里体现了

tweety0930

2楼的说法很对，矿就是一个option，成本大于现价就开采(exercise)，否则就封存（not exercise）.最规矩的估值就是建立binary tree.然后求用各个阶端cf的期望值求npv。npv>0开采，否则封存等待。

但此题是一个特殊情况，价格等可能的增加或减少相同的数量。叫他random walk（discrete）也好，布朗运动(continuous)也罢，各个阶段的均值（期望值）都等于现值 $4/pound。

所以问题就简化了：PMT=（4-3.6）*100,000=40,000， N=4， I/Y=10% 得到 PV=126,795

PV > initial outlay (100,000)

也就是 NPV = 26,795> 0

理论上可以马上开采

tweety0930

“矿就是一个option，成本大于现价就开采(exercise)，否则就封存（not exercise）.”

说反了。见笑

不能编辑了
[em04]