NGOs and international development: A review of thirty-five years of scholarship

•Systematic review using computer-assisted content analysis on 3336 articles and in-depth coding of 300 articles.•NGO literature is structured by six foundational research questions.•This interdisciplinary literature is dominated by case studies and has become more quantitative over time.•Research “goes where the action is” and leaves geographic and sectoral gaps.•Literature tends to report positive effects of NGO interventions in health and governance. Since 1980, the number of non-governmental organizations (NGOs) in developing countries has exploded. Published research on NGOs has paralleled this growth, yet there exists scant synthesis of the literature. This article presents a synthesis, while also introducing a collaborative research platform, the NGO Knowledge Collective. We ask four questions: first, who studies NGOs, and how do they study them? Second, what issues, sectors and places are studied when NGOs are the focus? Third, what effect do NGO activities have on specific development outcomes? And fourth, what path should the NGO research agenda take? To answer these questions, we conduct a mixed-method systematic review of social science publications on NGOs, which includes computer-assisted content analysis of 3336 English-language journal articles (1980–2014), alongside a close, qualitative analysis of 300 randomly selected articles. We find, first, that interdisciplinary journals dominate NGO publishing, that research on NGOs is more qualitative than quantitative, and that practitioners publish, but Northern academics create most published knowledge. Second, we find the literature is framed around six overarching questions regarding: the nature of NGOs; their emergence and development; how they conduct their work; their impacts; how they relate to other actors; and how they contribute to the (re)production of cultural dynamics. Articles also focus disproportionately on the most populated and/or politically salient countries, and on the governance and health sectors. Third, we find that scholars generally report favorable effects of NGOs on health and governance outcomes. Fourth, we propose a research agenda calling for scholars to: address neglected sectors, geographies, and contextual conditions; increase author representativeness; improve research designs to include counterfactuals or comparison groups; and better share data and findings, including results from additional, focused NGO-related systematic reviews. Implementing this agenda wil