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The federal individual income tax has had many more brackets and much higher rates in the past than it does today. In 1958, for example, there were 24 brackets (versus 6 today) and the top rate was 91 percent (versus 35 percent today). The impact of more brackets and higher rates on taxpayers and revenues depends on how much taxable income falls in each of the tax rate brackets. We find that only a small fraction of returns was subject to rates above todays top rate of 35 percent in any year since 1958, but a significant fraction of tax was paid at these higher rates in many years. For example, prior to 1982 (when the top rate was reduced to 50 percent), taxable income in brackets above todays top 35 percent rate was taxed at an average effective rate of 49 percent. We estimate that increasing the effective tax rate on taxable income in the 35 percent bracket to 49 percent would have raised $78 billion of additional income tax revenue in 2007.