Some deductions are before the AGI (referred to by tax professionals as dfors or adjustments) and other deductions appear after the AGI (referred to by tax professionals as from or merely deductions). Do each of the following: Select a deduction for AGI and explain how the deduction works, why Congress allows that deduction (what policy aims it serves), and why it should be a deduction for AGI rather than from AGI. What impact would switching that deduction to a deduction from AGI have? Explain why AGI is so significant in the determination of tax liability.