Elena, aged 61, lives in a state that levies no income tax and is in the 32 percent federal marginal bracket. Her planner is comparing a general obligation municipal bond yielding 3.20 percent, the interest on which is exempt from federal income tax, with an investment grade corporate bond of similar maturity and credit quality. Ignoring the net investment income tax and any transaction costs, what pre-tax yield must the corporate bond offer for Elena to be indifferent between the two?
- A4.71 percent Correct
- B2.18 percent
- C4.10 percent
- D4.22 percent
Why A is correct: Correct. Dividing the tax free yield by one minus the marginal rate gives 3.20 divided by 0.68, which is 4.7059 percent, or 4.71 percent rounded, the taxable yield that leaves 3.20 percent in Elena's hands after federal tax.
Why B is wrong: This is 3.20 multiplied by 0.68, which converts a taxable yield into an after-tax yield. It runs the adjustment backwards, since the municipal yield is already an after-tax figure and has to be grossed up rather than reduced.
Why C is wrong: This is 3.20 divided by 0.78, grossing the yield up at a 22 percent rate. The taxable equivalent yield uses the investor's marginal rate on the next dollar of interest, which the stem states is 32 percent, rather than a lower bracket rate.
Why D is wrong: This is 3.20 multiplied by 1.32, adding the marginal rate to the yield instead of dividing by one minus the rate. The shortcut looks close at low rates but understates the gross-up, and the error widens as the marginal rate rises.