Emmanuel Saez and Thomas Piketty have spent the last decade tracking the incomes of the poor, the middle class and the rich in countries across the world. More than anything else, their work shows that the top earners in the United States have taken a bigger and bigger share of overall income over the last three decades, with inequality nearly as acute as it was before the Great Depression.

A new understanding of the economics of taxation - For 30 years, any proposal to raise taxes had to overcome an unshakable belief that higher taxes inevitably led to less growth. The belief survived the Clinton administration, when taxes rose and the economy surged. It survived George W. Bush s administration, when taxes were cut yet growth sagged. But now, a growing body of research suggests not only that the government could raise much more revenue by sharply raising the top tax rates paid by the richest Americans, but it could do so without slowing economic growth. Top tax rates could go as high as 80 percent or more.