The Poverty Action Lab at MIT aims to improve the effectiveness and efficiency of other organizations' anti-poverty programs. They use rigorous experimental social science methods, conducting randomized studies to evaluate the effectiveness of programs around the world. They partner with anti-poverty organizations to help them evaluate and improve their programs, publish their evaluations on their website and sometimes in academic journals, and consult with other aid organizations (including the World Bank) to encourage them to use more of an experiment-based methodology. They take donations.

For more info you can look through the Poverty Action Lab website, see this Esquire article, or this subscription-only article in Nature.