 He subsequently traveled to the United States to earn a master's degree in food science and international nutrition at Cornell University in 1978.After a brief stint in government working in Colombia's Department of National Planning, in Bogota, from 1981 to 1982, in 1987 he received an interdisciplinary Ph.D from the University of California, Berkeley, in Development Philosophy, Policy and Planning.He has taught mainly at U.S. universities, including the University of Massachusetts Amherst, but also abroad at institutions in Colombia, Finland, Spain, and England.