Social welfare is a complex, multi-dimensional, field of practice that seeks to promote the well-being of people everywhere. But national responses to social welfare differ dramatically from one society to the next and, often, valid comparisons between different nations and systems of social welfare are difficult to undertake. This paper addresses that issue by introducing an innovative approach to welfare policy analysis using a Private-Public Development Mix (PPDM) model. The PPDM draws on all four of social welfare’s core institutions—the State, the family & household, the Market, and Civil Society Organizations (CSOs)—as well as four sets of social challenges for which national and international policy responses are needed. The utility of the model is demonstrated through analyses of public-private responses to poverty alleviation efforts in the United States and to advancing compulsory primary and middle school education among rural children living in two of China’s poorest regions.