S2000, can you kindly apply the logic (you explained on your link above) to 2013 AM or 2009 AM (as examples), as the official solution does neither (of the two cases) of what you have explained?
They seem to adjust PMT (Cash flow) for “after” or “before” tax
2013: It is a taxable portfolio, and withdrawals are taxed.
Investable asset = 2,500,00 + 10,000,000 (1-0.15) – 250,000 = USD 10,750,000
PMT (next year cash) = 300,000 (1+2.5%) – 125,000 (1-0.30) = USD 220,000
i/y = 220,000 / 10,750,000 = 2.05%
- Inflation (2.5%) = 4.55% ( after tax nominal)
2009: only withdrawals are taxed.
Investable asset = 1,100,000 – 100,000 = USD 1,000,000
PMT (next year cash) = 125,000 – 80,000 (after tax) = USD 45,000 (after tax)
PMT (pre-tax cash flow) = 45,000/(1-0.20) = 56,250
i/y = 56,250 / 1,000,000 = 5.625% (pre-tax)
- Inflation (4.0%) = 9.625 % ( after tax nominal)
2015: Question #7 (b), taxable portfolio and withdrawals are taxed – although its used in a gift context but it still uses PV/FV/PMT/i/y concept.
This is the only question where they have adjusted i/y (from pre-tax to post-tax), i.e. going from 8% (pre-tax) to 6% (post-tax)