I am so confusing with the terminology of real, after-tax/ pretax and nominal/ real return in private wealth management. Please correct me my following understanding about 04 following formulas:
Given a situation that you have $1 and invest in 1 year.
Formulas 1
1* (1 + R real pretax ) * (1 + inflation) = 1 * (1 + R nominal pretax )
With tax effect, we have
Formulas 2:
1* (1 + Inflation) + R real pretax * (1 + inflation) * (1 - Tax) = 1 + 1* R nominal pretax * (1 - Tax)
Formulas 3:
(1 + inflation) + R real after tax * (1 + inflation) = 1 + 1 * R nominal after tax
Formulas 4:
R nominal pretax = [R real after tax * (1+ inflation) + inflation] / (1-T)
It all depends on if the investment is taxable or not taxable. if it is taxable, you add inflation and then dividend by (1-T) and if it only the withdraw portion of the return is taxable, you divide by (1-T) and then add inflation. Read the question carefully to know what they want you to do.
Fully taxable: R nominal pretax = [( R real after tax + inflation)] / (1-T)
Only return portion is taxable (for example a TDA): R nominal pretax = [( R real after tax ) / (1-T)] + inflation