[3] His work, done with Thomas Piketty and Gabriel Zucman, includes tracking the incomes of the poor, middle class and rich around the world.

Their work shows that top earners in the United States have taken an increasingly larger share of overall income over the last three decades, with almost as much inequality as before the Great Depression.

They found substantial geographic differences across the country that were correlated with five factors: segregation, income inequality, local school quality, social capital, and family structure.

[12] He was the recipient of the 2009 John Bates Clark Medal, awarded to "that American economist under the age of forty who is judged to have made the most significant contribution to economic thought and knowledge.

The 2009 John Bates Clark citation reads:[14] "[Saez's] work attacks policy questions from both theoretical and empirical perspectives, on the one hand refining the theory in ways that link the characteristics of optimal policy to measurable aspects of the economy and of behavior, while on the other hand undertaking careful and creative empirical studies designed to fill the gaps in measurement identified by the theory.