According to UC Berkeley economists Emmanuel Saez and Gabriel Zucman, all of the Democratic candidates’ plans increase tax rates on the rich but to very different degrees: Joe Biden is the most moderate; Sanders’s and Warren’s plans sharply increase progressivity. Overall, the Buttigieg plan raises 3.9 percent of national income extra in taxes, more than Warren (3.2 percent), Sanders (2.6 percent), and Biden (1.5 percent).