This paper by D. Coady, I. Parry, L. Sears and B. Shang estimates fossil fuel subsidies and the economic and environmental benefits from reforming them. It mostly focuses on a broad notion of subsidies arising when consumer prices are below supply costs plus environmental costs and general consumption taxes. Estimated subsidies are USD4.9 trillion worldwide in 2013 and USD5.3 trillion in 2015 (6.5% of global GDP in both years). Access to this paper is available to purchase on the ScienceDirect website.