Matthew Warning’s research focuses on rural poverty in developing countries and project impact analysis. Since 2000 he has been researching smallholder coffee communities in Latin America and Africa, in particular in Mexico, Peru, Brazil, Rwanda, and Burundi. Following fieldwork studies of the impact of fair trade on small-scale producers, he served as a "stakeholder" commentator for the Starbucks Corporate Social Responsibility Report; as advisor to the University of Washington Burke Museum’s exhibit, Coffee: The World in Your Cup; and as consulting producer and content specialist for the PBS documentary Buyer Be Fair: The Promise of Product Certification, which looked at fair trade coffee and certified wood. Warning has presented papers internationally and regionally on sustainable coffee production. In his earlier work on rural communities in developing countries, he focused on how agrarian institutions substitute for poorly functioning or nonexistent markets in environments with high transactions costs and imperfect information. He did extensive fieldwork in Africa, most significantly in Senegal and Tanzania. Warning has published in journals including World Development and Journal of Development Studies. He teaches courses on development economics and econometrics.