Kim and Kayne have been dating for years and are now thinking about getting married. As a financially sophisticated couple, they want to think through the tax implications of their potential union.

a. Suppose Kim and Kanye both earn $72,000 (so their combined income is $144,000).

Using the tax bracket information

Taxable Income Tax Rates Individual Returns Joint Returns 10.0% $0 to $9,075 $0 to $18,150 15.0% $9,076 to $36,900 $18,151 to $73,800 25.0% $36,901 to $89,350 $73,801 to $148,850 28.0% $89,351 to $186,350 $148,851 to $226,850 33.0% $186,351 to $405,100 $226,851 to $405,100 35.0% $405,101 to $406,750 $405,101 to $457,600 39.6% Over $406,750 Over $457,600

, calculate the combined tax bill that they would pay if they remain single, and compare that to the taxes they would pay if they were married and filed a joint return.

b. Now suppose that Kim and Kanye both earn $110,000 (so their combined income is $220,000).

Calculate the combined tax bill that they would pay if they remain single, and compare that to the taxes that they would pay if they were married and filed a joint return.

c. What differences do you find in parts (a) and (b)? What is the cause of these differences?