In: Statistics and Probability
Asset A pays $1,500 with certainty, while asset B pays $2,000 with probability 0.8 or $100 with probability 0.2. If offered the choice between assets A and B, a particular decision maker would choose asset A. Asset C pays $1,500 with probability 0.25 or $100 with probability 0.75, while asset D pays $2,000 with probability 0.2 or $100 with probability 0.8. If offered the choice between assets C and D, the decision maker would choose asset D. Show that the decision maker's preferences violate the independence axiom.
PLEASE HELP SHOW WORK PLEASE!!
First, let us compute the expected choice for each asset:
if then
where, Z = $100 and p is the probability
For A:
E(A) = 1500 (1) + 100 (0)
= $1500
E(B) = 2000 (0.8) + 100 (0.2)
= 1600 + 20
= $1620
Hence, for B> A, E(B) > E(A), but he prefers A over B
E(C) = 1500 (0.25) + 100 (0.75)
= 375 + 75
= $450
E(D) = 2000 (0.2) + 100 (0.8)
= 400 + 80
= $480
Hence, for D>C, E(D) > E(C), and he prefers D over C.
Hence, if the decision maker is ready to take a greater risk, and prefers D over C then he must also take the greater risk in case of A and B, i.e. choose B over A.
If he goes according to the independence axiom, his preference should be:
D>C and B>A .......(Greater risk taker) or prefers $ 480 over $ 450 and $1620 over $1500
C>D and A>B ......(More of a safe player) i.e prefers $ 450 over $ 480 and $1500 over $1620
But here, the decision maker has chosen A>B and D>C, i.e he prefers A>B (a safe player here), while acts as a risk taker when he prefers D>C.Hence, it is a violation of the independence axiom.