Such efforts -- which include taking more compensation in the form of tax-advantaged health-care benefits -- reduce revenue for the government and "increase deadweight losses" for the economy, he added.
Very high top tax rates also may have long-run effects on growth that aren't immediately discernible, said Joel Slemrod, chair of the economics department at the University of Michigan in Ann Arbor.
"New people coming into the labor force might decide it's not worth it" to try so hard to get ahead, he said.
Depressed Labor Supply
High taxes have depressed the labor supply in European economies, according to economist Edward C. Prescott, a Nobel laureate, who argues that Americans generally work more hours because U.S. tax rates are lower. The result: U.S. inflation- adjusted GDP per capita in 2010 was about 40 percent higher than the average for the euro area, according to data from the Organization for Economic Cooperation and Development in Paris.
"This is nonsense," said the Picketty, 40, a visiting professor at MIT in 2000-2001. "When people in Europe have five weeks of vacation, this is not in response to high tax rates."
Saez, 39, said increases in top rates should be coupled with steps to close loopholes and broaden the tax base to limit the avoidance efforts Feldstein worries about.
Capital-gains taxes should be raised as well, said Saez, a French and U.S. citizen. That would discourage business leaders from trying to take more of their compensation in shares, rather than salary, to avoid paying higher income-tax rates. The top U.S. rate on long-term gains is 15 percent.
Move Together
Taxes on capital and labor income earned by the wealthy "don't have to match, but they should move together and shouldn't be too far apart," Diamond said.
An increase would hurt the stock market and the economy, argued Romney adviser Hubbard, who is also dean of the graduate business school at Columbia University in New York.