Independent solution
How to solve this Growing Perpetuity Duration question
Setup
Setup
Discounted payments in the growing perpetuity form a geometric sequence with ratio q = 1.02/1.05. Treat q as the discount factor for an equivalent level perpetuity.
Model
Model
The weighted-average payment time is therefore the level-perpetuity duration under the net rate, equal to (1 + i)/(i − g).
Compute
Compute
Using i = 5% and g = 2% gives 1.05/0.03 = 35 years.
Answer
Answer
The calculation gives 35 for growing perpetuity duration, matching published choice B.