During his student days he joined the Frente de Estudiantes Revolucionarios (FER), remaining a member until 1973.

[3] He worked as a researcher, between 1975 and 1978 in the Centre d'Etudes Prospectives d'Economie Mathématiques Apliquée à la Planification (CEPREMAP); from 1978 to 1984 in the Centre National de la Recherche Scientifique (CNRS) and in the Institut Français de Recherche pour le Développement en Cooperation.

After 1985, he began to emerge as one of the best-regarded left-wing economists, and in 1989 became assistant coordinator of the economic programme of the Concertación.

[4] In 1993 he supported the nomination for President by the Concertación of Ricardo Lagos, who was defeated by the Christian Democrat (DC) candidate Eduardo Frei.

[12][13] In June 2011 he was awarded the Japanese honour "The Order of the Rising Sun" by the Emperor Akihito in the Imperial Palace in Tokyo.