a) As discussed in class, what is the approximate amount of the current U.S. national debt? Has this amount been increasing or decreasing recently? Why does the United States need to borrow this money? In your response, be certain to briefly explain the difference between the amount of the current U.S. national debt and the current U.S. federal budget deficit. b) When you share this information with a friend, she asks whether the U.S. federal income tax is a "good tax." Identify and provide a brief explanation of the four basic standards commonly used to evaluate a tax system. Assess the degree to which the current U.S. federal income tax system meets each of the standards. In addition, for each of the four standards, provide a specific reason why it can be difficult for the United States to put that standard into practice when designing and maintaining the federal income tax. c) Your friend now asks why the U.S. federal government does not simply raise individual income tax rates to increase the amount of income tax that it collects. Explain to your friend the difference between the income effect and the substitution effect on the behavior of U.S. taxpayers, and using your own numbers, create a basic example to show how the total tax collected could actually decrease even though tax rates are increased. d) Your friend wants you to explain why a progressive rate structure is used in the United States for the individual income tax rather than a proportionate (constant, flat tax) rate structure, such as that commonly used for sales and use taxes. After providing your brief explanation, use one of the 2020 tax rate schedules from Appendix D to identify and explain the specific tax rates that an individual will be subject to when taxable income equals $20,000. Compare and contrast this situation to the specific tax rates that an individual will be subject to when taxable income equals $1 million