32) The nominal interest rate on taxable bonds is 8%, while on municipal bonds (which aren’t
taxable) it is 5%. The expected inflation rate is 3% and the tax rate on interest income is 40%.
Calculate the expected after-tax real interest rate on both bonds. Which would be the better
investment? Now suppose the actual inflation rate turned out to be 6%. Which bond was the
better investment? Would your answer change if inflation had turned out to be 0%?
33) Suppose you divide your life into two periods-working age and retirement age. When you
work, you earn labor income Y; when retired, you earn no labor income, but must live off your
savings and the interest it earns. You save the amount S while working, earning interest at rate r,
so you have (1 + r)S to live on when retired. Because you don’t need to consume as much when
retired, you want to set consumption when working twice as high as consumption when retired.
(a) Suppose you earn $1 million over your working life, and the real interest rate for retirement
saving is 50%. How much will you save and how much will you consume in each part of your
life?
(b) Suppose your current income went up to $2 million when working. Now what will you save
and how much will you consume each period?
(c) Suppose a social security system will pay you 25% of your working income when you are
retired. Now (with Y = $1 million, as in part (a) how much will you save and how much will you
consume each period?
(d) Suppose the interest rate rises (starting from the situation in part (a). Will you save more or
less?