The table below gives the taxable income and taxes for three taxpayers under a hypothetical tax system. Income Taxes Tax Rate A $30,000 $12,000 B $50,000 $17,500 C $100,000 $30,000 Is the tax rate structure of this tax system proportional, regressive, or progressive? Give a real world example of a type of tax that has this tax rate structure: QUESTION 4 Select the correct combination of answers: The idea that some people will work fewer hours after a tax rate decrease because they care about maintaining the same after-tax income is referred to as the (Income / Substitution) effect. The idea that some people will work more hours after a tax rate decrease because the after-tax returns to work are greater is referred to as the (Income / Substitution) effect. A. Income; Income B. Income; Substitution C. Substitution; Income D. Substitution; Substitution