Brian Galle, a UC Berkeley tax law professor and co-author of the billionaire tax, called Saez “one of the real geniuses of our time.” It’s not just that Saez has won a John Bates Clark Medal, the most prestigious economic laurel not named the Nobel Prize. Working with him, Galle said, “can sometimes feel like the tax-policy equivalent of a 10-day-contract guy trading passes with LeBron James.”