How high could it be?

Currently the top marginal rate of federal income tax is 35%, which means that Bill Gates pay 35 cents for the last dollar that he earns every year. Does it sound high or low? That is your personal call.

Let's just put it in historical perspective (See the graph to the right). It is shocking to know that there were 14 years that we have the top marginal rate over 90%. The record high was 94% during 1944-1945, at the end of WWII. Yet the high rate was not due to the war itself. It was a little peak among a half-decade long period of 70% or above, from 1930s to 1980s.

Top US Marginal Income Tax Rates (1913-2003)