Gabriel Zucman started his first real job the Monday after the collapse of Lehman Brothers. A decade later, Zucman, 32, is an assistant professor at the University of California at Berkeley and the world's foremost expert on where the wealthy hide their money. His doctoral thesis ... exposed trillions of dollars' worth of tax evasion by the global rich. For his most influential work, he teamed up with his Berkeley colleague Emmanuel Saez. Their 2016 paper, Wealth Inequality in the United States Since 1913," distilled a century of data to answer one of modern capitalism's murkiest mysteries: How rich are the rich in the world's wealthiest nation? The answer - far richer than previously imagined - thrust the pair deep into the American debate over inequality. Zucman and Saez's latest estimates show that the top 0.1% of taxpayers - about 170,000 families in a country of 330 million people - control 20% of American wealth, the highest share since 1929. The top 1% control 39% of U.S. wealth, and the bottom 90% have only 26%. The bottom half of Americans combined have a negative net worth. The shift in wealth concentration over time charts as a U, dropping rapidly through the Great Depression and World War II, staying low through the 1960s and '70s, and surging after the '80s as middle-class wealth rolled in the opposite direction. Zucman has also found that multinational corporations move 40% of their foreign profits, about $600 billion a year, out of the countries where their money was made and into lower-tax jurisdictions.