In less than a generation, we have witnessed a tectonic shift in the way people think about—and work toward—social change. The groundswell of new activism — social entrepreneurship — is manifest across society as innovative change makers test new solutions to entrenched social, economic, and environmental problems. This course is designed for students who are interested in understanding and participating in social entrepreneurship, whether they pursue careers (or avocations) in the nonprofit, private or public sectors. The course gives an overview of the field, with in depth examples and case studies of innovative change makers and organizations in the nonprofit, private and public sectors that illuminate the traits and tools of the new activism: a heightened emphasis on measurement and evaluation; an embrace of competition in a number of forms, including the design and implementation of market based instruments like prizes and challenges; the development of ‘laboratories’ to foster social innovations which can then be brought to scale; experiments with technology and the use of open and crowd source solutions to social change; and a new thinking about asset management and investment, the nature of social value and returns, and the sources of capital available to address chronic social problems. The course also explores the opportunities and tensions inherent in cross-sector work: the definition of public goods, the respective roles that philanthropy, government and commercial actors play in providing them, and the innovations that occur when partnerships form across the sectors.