Fossil fuel subsidy reform has in recent years been addressed by international economic organizations including the International Monetary Fund (IMF) and the Organisation for Economic Co-operation and Development (OECD). The two organizations have differed significantly in how they define fossil fuel subsidies. The IMF’s definition constitutes a radical break with previous definitions by including environmental externalities, while the OECD’s is more conventional. This article by J. Skovgaard in International Environmental Agreements explores factors explaining why these international economic organizations have approached fossil fuel subsidies so differently. The article is available to download on the Research Gate website.