Fullerton previously held positions as Senior Economist at the University of Florida Bureau of Economic and Business Research, International Economist at Latin America Service of the WEFA Group (formerly known as Wharton Econometrics), and Economist in the Executive Office of the Governor of Idaho. At WEFA, Fullerton was in charge of modeling, forecasting, and policy analysis for the South American economies of Colombia, Ecuador, and Venezuela. His research has been published in academic journals in Asia, Africa, Europe, North America, and South America.