2. Which system is used in the U.S.?
The U.S. federal income tax uses a progressive tax system, where higher incomes are taxed at higher rates.
Note: some taxes, like sales tax and payroll taxes, can be regressive, but the overall income tax structure is progressive.
3. Which system is the most fair and/or effective? Explain why
The progressive tax system is the most fair and effective because it asks more from people who can afford it and uses the funds to support public services that everyone uses.
It also helps reduce income inequality by redistributing resources through government programs.
Other systems are simpler, but they tend to be less fair in practice.