Lionized by Republicans, the late Ronald Reagan championed an across-the-board tax cut soon after he became president in 1981 that lowered the top rate to 50 percent from 70 percent. He subsequently pushed it to 28 percent as part of an overhaul of the tax code in 1986.

The economy actually grew faster in the 30 years before that tax cut than it did during the following three decades, according to Diamond and Saez. Gross domestic product per capita advanced at an average annual 2.2 percent rate between 1950 and 1980, compared with 1.7 percent between 1980 and 2010, their calculations show.

Internationally, advanced economies that have reduced top tax rates the most since 1975 haven't shown a tendency to grow faster than those that cut less, Picketty, Saez and Stefanie Stantcheva, an economist and Ph.D. student at MIT, found in the November 2011 paper.

Faster Growth

Their data ignore such emerging-market economies as Brazil and India, which have lowered top tax rates and enjoyed faster growth than developed nations, said Alan Reynolds, a senior fellow at the Cato Institute in Washington.

Brazil's economy has expanded at an average annual pace of 3.6 percent since 2000, more than double the 17-nation euro area's 1.4 percent.

The British government is worried enough about the economic impact of high taxes on the wealthy that it has said it will reduce its top rate to 45 percent next year from 50 percent now.

No government "can justify a tax rate that damages our economy and raises next to nothing; it's as simple as that," Chancellor of the Exchequer George Osborne told Parliament in London on March 21.

Tax Avoidance

It's not only through "reduced work effort" by the rich that higher tax rates can hurt the economy, Martin Feldstein, a professor at Harvard University in Cambridge, Massachusetts, said in an e-mail. Stepped-up tax avoidance also can impede economic efficiency by diverting money and attention away from more productive purposes, said Feldstein, president emeritus of the National Bureau of Economic Research, which determines when U.S. recessions begin and end.