By focusing on cooperation, this paper presents an econometric analysis of the determinants of successful collective action. The paper is based on a survey of 104 peasant cooperative institutions in Paraguay. The article presents a literature review on cooperation followed by the study methodology and discussion. Results show that strong local people's organizations are paramount to sustainable projects. They improve productivity and provide credit where governments are not able to. Local people's organizations can provide the political base to seek income distribution. The presence of women and social capital can strengthen and increase cooperation.