The most severe impact of the Ebola epidemic, which began in Guinea in December 2013 and quickly spread to Liberia and Sierra Leone, has been in lost human lives and suffering. This report, prepared for the World Economic Forum at Davos, focuses on the indirect, economic costs, in particular the effects on economic output in 2015. Most of the economic cost is driven by aversion behavior, which consists of both the actions taken by individuals to avoid exposure to the illness and actions taken by investors in anticipation of those individual choices. The report first estimates the impact of the epidemic on gross domestic product (GDP) in Guinea, Liberia, and Sierra Leone. The report builds on sector-specific analysis to update World Bank forecasts for the three countries, and incorporates recent results of World Bank-financed cellphone surveys in Liberia and Sierra Leone. The authors evaluate the economic effects of the epidemic on the continent, beyond the three hardest-hit countries, using assessments by World Bank country economists across the 48 countries of sub-Saharan Africa. Finally, the report updates estimates from the global economic model of the research arm of the World Bank, to quantify the 2015 impact of the potential spread of the epidemic to other countries. Updated general equilibrium analysis suggests that further spread of the epidemic to other African economies, if the epidemic is not contained and instances of infection continue to occur in other countries, can potentially exact an economic toll of the order of 6 billion dollars. The results underscore the importance of: Ebola and broader pandemic preparedness in African countries; and reaching the goal of zero new cases as soon as possible in the three most affected countries.