**Question 999** duration, duration of a perpetuity with growth, CAPM, DDM

A stock has a beta of **0.5**. Its next dividend is expected to be $**3**, paid **one** year from now. Dividends are expected to be paid annually and grow by **2**% pa forever. Treasury bonds yield **5**% pa and the market portfolio's expected return is **10**% pa. All returns are effective annual rates.

What is the Macaulay **duration** of the stock now?