Professor of Political Science, director of Stanford's Center for Ethics in Society, co-director of the Center on Philanthropy and Civil Society, and associate director of the Institute for Human-Centered AI. He is the author of System Error: Where Big Tech Went Wrong and How We Can Reboot (with Mehran Sahami and Jeremy M. Weinstein); Just Giving: Why Philanthropy is Failing Democracy and How It Can Do Better; and Digital Technology and Democratic Theory (edited with Lucy Bernholz and Hélène Landemore). His teaching and writing these days focuses on ethics, policy, and technology. He is the recipient of multiple teaching awards, including the Walter J. Gores award, Stanford’s highest honor for teaching. He played a role in creating Giving Tuesday, and currently serves as chair of its board.