Original practice · fully worked
Original variant: yield inferred from an estimated arts-bond portfolio value
An arts portfolio contains a 40,000 bond of Macaulay duration 5 and a 60,000 bond of duration 9, both valued at 4% yield. Using the Macaulay approximation, a new portfolio value of 105,000 implies what annual yield?
- A
2.80% - B
3.00% - C
3.32% - D
3.60% - E
4.20%
Answer and calculation
Portfolio duration is 7.4; inverting the 1.05 value ratio gives yield 3.32%, choice C.
Setup
Setup
Market-value weights 40% and 60% produce the portfolio duration.
DP=0.4(5)+0.6(9)=7.4 Model
Model
A five-percent estimated value increase implies a yield below the original 4%, and the yield-factor ratio can be inverted.
1.05=(1+i1.04)7.4 Compute
Compute
Taking the 7.4th root gives an implied yield of 0.0331656.
i=1.051/7.41.04−1=0.0331656 Answer
Answer
The estimated annual yield is 3.32%, corresponding to choice C.
i=3.32%(C)