risk and decisions Flashcards
what is the discount factor?
1/ [(1+r)^n]
what do we need to know to find the present value?
the size of the cash flow
when it arrives
the interest rate (sometimes called the cost of capital or the required rate of return)
how do you deal with uncertainty with the annual sales?
if the annual sales are uncertain, we can work out an expected value of sales using probabilities. if there are three states of the world, low medium and high demand and we are told the possible sales levels and their associate probabilities. simply apply the cash flow per unit to get cash flows in each state of the world. then apply the probabilities to calculate the expected cash flow for each year and then sum up the states.
what is the expected utility function?
U(x) = [ p1 x u(X1)] + [p2 x u(X2)] …. + [pn x u(Xn)]
what is the utility of the expected payoff?
the utility obtained by the expected payoff ( the money itself)
what is the expected utility of the payoff?
this is the expected utility of the possible payoff (this is like the utility of the gamble)
what does it mean to be risk neutral
the agents only care about the expected value ie u(x)=x
U[E(x)] = E[U(x)]
what does it mean to be a risk seeker?
risk seekers are more willing to take risk - U[E(x)] < E[U(x)]
what does it mean to be risk averse?
agents dislike risk so the u(x) is concave - U[E(x)] > E[U(x)]
what is a certainty equivalent?
it is the value of the payoff which if we know we will have it with certainty, gives us the same utility as the risky payoff. in other words if you have a gamble which could give you an expected pay off of £x, how much certain money would give you the same utility
how do you calculate the certainty equivalent?
you start with a utility function, for example lets say you have a risk averse with a function of u(x) =x^0.5. imagin a pay off with 4 and 9 with 50/50 chance. so 0.5x4^0.5 + 0.5 x 9^0.5 = 2.5 = E[U(x)]. you now work backwards with in this case squaring it to find the certainty equivalent so 2.5^2 = 6.25 which is equivalent to the expect 6.5= 4x0.5 + 9x0.5
what is the markowitz risk premium?
the difference betweent the expect pay off and the certainty equivalent
what does the utility(x) against x look like for a risk neutral person?
the curve is a straight line for a risk neutral person
what does the utility(x) against x look like for a risk averse person?
the curve is concave for a risk-averse person
what does the utility(x) against x look like for a risk seeking person?
the curve is convex for a risk seeker