입법조사처는 “소득수준에 따라 한계세율이 높아져 소득공제 제도가 조세지출의 수직정 형평성을 저해한다”며 소득계층간 과세형평성 제고를 위해 세액공제로의 전환 검토도 제안했다.
"The income tax deduction system undermines the vertical balance of tax expenditure by increasing the marginal tax rate according to the level of income," the Legislative Research Service said. It also proposed a review of a switch to tax deduction to enhance the taxation balance between income brackets.