Program on Philanthropy and Social Innovation (PSI) Grantmaking foundations, nonprofit organizations, social enterprises and public-private partnerships offer lasting solutions to societal challenges. They are at the heart of civil society. This program seeks to inform and maximize the impact of these social sector actors through leadership development initiatives, convenings, and communications so that each can contribute to the good society at home and abroad. The program’s theory of change rests on the premise that if their leaders have clarity about their values, are collaborative in their approach to problem-solving, and are aware of the strategies and potential partnerships available to them, they are more likely to succeed in advancing the social good.