Some economies are “black holes” where reliable data is scarce due to government control, low capacity, or conflict. Despite these challenges, researchers have found ways to gather useful information. This paper draws on the literature on North Korea to review six key methods: satellite imagery, reports from aid agencies, trade data, prices, refugee surveys, and official documents. These sources are imperfect, and require close attention to research design and measurement error. Nonetheless, they demonstrate that it is possible to extract information from economic black holes and to draw meaningful insights about them.