In: Statistics and Probability
I have been getting many incorrect answers recently, if you are unsure please do not attempt. All i ask is all parts answered and with shown or explained work. Thank you (:
Delaware National Golf Club went out of business during the recent downturn in the economy (a sad day in the Donnelly household). Susan is a real estate developer who would like to build houses on a portion of it. To do so Susan will need the approval of the county government to change how the land is zoned. The following decision table shows the scenario's payoffs and probabilities.
Market |
||
---|---|---|
Alternative |
County Approval |
No County Approval |
Purchase land |
$1,500,000 |
−$1,600,000 |
Don't purchase land |
$0 |
$0 |
Probability |
0.30 |
0.70 |
Susan has the choice of purchasing an option to buy the land next year for $30,000. This will give her the opportunity to gain the support of the homeowners on the golf course, which will increase the likelihood of the county approving the zoning change. Susan estimates there is a 40% chance she will be able to obtain the support of the residents. With the support of the residents, the probability that the county will approve the zoning change is 56.6%. Without the residents' support, the probability of the county's approval is only 12.1%.
a. Construct a decision tree to recommend a course of action for Susan.
b. What is the most that Susan should pay to purchase the option to buy the land?
At the first level Susan has 2 choices, buy an option or don't buy an option. Isshe does not buy the option then she has 2 choices, purchase or don't purchase the land
If she buys the option then she can obtain the support of residents or fail to obtain the support.
Either case she has 2 choices, purchase or don't purchase.
a) The decision tree is given below
To calculate the expected value, we start from rigth to left
she has to spend $30,000 on the option
payoff if she gets approval is $1500,000-30,000 = $1,470,000 with a probability of 0.566
payoff if she does not get approval is -$1,600,000-30,000= -$1,630,000 with a probability of 0.433
The expected value of node 7 is
she has to spend $30,000 on the option
payoff if she gets approval is $1500,000-30,000 = $1,470,000 with a probability of 0.121
payoff if she does not get approval is -$1,600,000-30,000= -$1,630,000 with a probability of 0.879
The expected value of node 8 is
Decision is between purchase land (EV=$124,600) and don't purchase land (-$30,000)
The optiomum decision is to purchase.
EV for node 4 is $124,600
Decision is between purchase land (EV= -$1,254,900) and don't purchase land (-$30,000)
The optiomum decision is don't purchase.
EV for node 5 is -$30,000
payoff if she gets approval is $1500,000 with a probability of 0.30
payoff if she does not get approval is -$1,600,000 with a probability of 0.70
The expected value of node 6 is
EV if support of residents is obtained is $124,600 with a probability of 0.40
EV if the support of residents is not obtained is -$30,000 with a probability of 0.60
EV of node 2 is
Decision is between purchase land (EV= -$670,00) and don't purchase land ($0)
The optiomum decision is don't purchase.
EV for node 3 is $0
At node 1 which is the decision node, there are 2 choices for Susan
If she buys the option then the expected payoff is $31,840
if she does not buy the option then the expected payoff is $0
Hence the optimum decision for Susan is to buy the option for $30,000
b) The expected payoff at node 2 calculated above is #31,840. This payoff is after subtracting the cost of option which is $30,000. That means the expected value of purchasing the option is 31,840+30000=$61,840
This value we will call as expected value with sample information EVwSI, as purchasing the option lets Susan to try to gauge if the residents are going to vote in favor or against the Golf course.
If she does not purchase the option then she will have to take a decision, without theextra help of the residents. The expected payoff then is $0. This we will call as expected value withpout the sample information EVwoSI
The expected value of purchaing the option then is
(expected payoff when option is purchased) - (expected payoff when option is not purchased)
=61,840 - 0 -= 61,840
Susan should be ready to pay at the most $61,840 to purchase the option to buy the land