Actually, high earners don't make enough money to close the current budget deficit. You'd need to raise taxes on middle-income earners too.
But we have had higher income tax rates in most of the years since World War II. What history and Table B-79 show is that even much higher rates -- like the 91 percent marginal rate on top earners imposed from the 1940s to the 1960s -- have never produced federal receipts higher than 20 percent of GDP.
Why is that? As the late Jack Kemp liked to say, when you tax something, you get less of it. When the government took 91 percent of what the law defined as adjusted gross income over a certain amount, not many people had adjusted gross income over that amount.
According to a Congressional Research Service study, the effective income tax rate on the top 0.01 percent of earners in the days of nominal 91 percent tax rates was only 45 percent. Others have pegged it at 31 percent.
In the 1970s, when the top rate on wage and salary income was 50 percent and 70 percent on investment income, high earners spent much of their time and energy seeking tax shelters. The animal spirits of capitalists, to use John Maynard Keynes' term, were directed less at productive investment and more at tax avoidance.
But don't European nations extract more in taxes from their citizens? Yes, but through consumption taxes like the value-added tax. But those taxes tend to be regressive, and in this country sales taxes have been the province of states and localities.
Barack Obama and the Democrats may well get higher tax rates. But it's not likely that high tax rates can ever generate enough revenue to fund unreformed entitlement programs.