As of 2007, there are about 138 million taxpayers in the United States. The Treasury Department in 2006 reported, based on Internal Revenue Service (IRS) data, the share of federal income taxes paid by taxpayers of various income levels. The data shows the progressive tax structure of the U.S. federal income tax system on individuals that reduces the tax incidence of people with smaller incomes, as they shift the incidence disproportionately to those with higher incomes – the top 0.1% of taxpayers by income pay 17.4% of federal income taxes (earning 9.1% of the income), the top 1% with gross income of $328,049 or more pay 36.9% (earning 19%), the top 5% with gross income of $137,056 or more pay 57.1% (earning 33.4%), and the bottom 50% with gross income of $30,122 or less pay 3.3% (earning 13.4%). If the federal taxation rate is compared with the wealth distribution rate, the net wealth (not only income but also including real estate, cars, house, stocks, etc) distribution of the United States does almost coincide with the share of income tax – the top 1% pay 36.9% of federal tax (wealth 32.7%), the top 5% pay 57.1% (wealth 57.2%), top 10% pay 68% (wealth 69.8%), and the bottom 50% pay 3.3% (wealth 2.8%).
Other taxes in the United States with a less progressive structure or a regressive structure, and legal tax avoidance loopholes change the overall tax burden distribution. For example, the payroll tax system (FICA), a 12.4% Social Security tax on wages up to $97,500 and a 2.9% Medicare tax (a 15.3% total tax that is often split between employee and employer) is a regressive tax on income with no standard deduction or personal exemptions.
The Center on Budget and Policy Priorities states that three-fourths of U.S. taxpayers pay more in payroll taxes than they do in income taxes. The Tax Foundation has stated that the burden of the corporate income tax (a 15-39% tax) falls on customers and workers of the corporations, who are often not rich.
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