Historically, international philanthropy has relied on a complex system of intermediaries to deliver goods and services in-kind to the poor. Donors to this system generally have little idea of how their money is used, how efficiently it is used, and whether the poor end up getting the things they value most. But recent breakthroughs in mobile banking technology are making it possible to radically simplify the system by sending money cheaply and securely to the poor and letting them decide for themselves what goals to prioritize. Paul Niehaus will discuss this new approach to philanthropy: what it implies for policy, what it implies for impact evaluation, and how GiveDirectly—the only non-profit devoted exclusively to making cash transfers—is implementing it.