You put money into an account that earns a 5 percent nominal interest rate. The inflation rate is 2 percent, and your marginal tax rate is 40 percent. What is your after-tax real rate of interest

Answer: 1%

Explanation:

The Nominal interest rate has not been adjusted for inflationary effects yet and as such is considered overstated.

The Real Interest rate has been adjusted for inflation and is believed to show the actual return one receives.

Tax is calculated on the Nominal rate.

After tax Nominal Rate = 5% * (1 - 40%)

= 3%

Then adjust for inflation to find real rate,

= 3% - 2%

= 1%

The After-tax real rate is 1%.