This project will examine the changing ways in which social scientists conceptualized, measured, debated, and addressed poverty in twentieth-century South Africa. It will explore the relationship between science, power, and the state. It will highlight the negotiated role of local intermediaries (Africans, teachers, translators, and field researchers) in the production of knowledge about poverty. And it will document the use of scientific expertise for negotiation, debate, and political claim-making against the state. Using predominantly English-language texts and targeted oral interviewing, I will compare three important periods: the emergence of the ''poor white problem" in the 1920s and '30s; the rise of poverty datum line studies in the 1940s and '50s; and the use of social science expertise to critique apartheid-era wage policies and living conditions in the 1960s-'80s. This project will trace the transformation of the poverty question from a racially exclusive concern to a powerful means of mobilizing social activism and international aid for black South Africans. Theoretically, the proposed research will contribute to African history and to the history of science. Practically, it will establish a historically-informed grounding for research and policy relating to poverty and so-called "basic needs" in Africa.