Your bank pays $0\mathrm{.}05$ on deposits, and you are in a tax bracket where you pay $40\%$ on interest income earned. The inflation rate is $0\mathrm{.}02.$ What is your after$-$tax real rate of return? If the answer is $1\%,$ then just write $0\mathrm{.}01.$ It is possible to have a negative after$-$tax rate rate of return.