The global recession has meant lower revenues from taxes on income, property sales and stock gains in most countries. Plus, many OECD countries cut taxes in the past year in hopes of jump-starting growth. Of 26 countries that reported provisional 2008 data to the OECD, 17 saw their tax-to-GDP ratios fall. And further recession-induced declines are expected when data for this year become available.

With trillion-dollar budget deficits forecast for several years and rising entitlement costs as Baby Boomers retire, many analysts say the U.S. tax take will rise.

"It's going to be politically painful. ... But our competitors are, for the most part, taxing themselves at higher rates," says Andrew Reschovsky, a professor of applied economics at the University of Wisconsin.