Gabriel Zucman is the intellectual force behind the movement to “tax the rich”. The French economist has worked alongside Senator Bernie Sanders, New York’s mayor, Zohran Mamdani, and Brazil’s president, Luiz Inácio Lula da Silva. But does his argument withstand scrutiny? The Economist’s acting business affairs, Henry Curr, sat down with Professor Zucman to discuss the concentration of wealth at the very top and whether there is a distinction to be made between good and bad billionaires. #