Independent solution
How to solve this Duration and Convexity question
Setup
Setup
A level perpetuity with its first payment in year one has Macaulay duration one plus i divided by i.
Model
Model
Deferring the first payment from year one to year five shifts every payment time four years later.
Compute
Compute
The resulting Macaulay duration is 15; converting to modified duration divides by 1.10.
Answer
Answer
The modified duration is 13.64, corresponding to choice A.