Dr. Chang is a senior researcher of Korea Institute for Industrial Economics and Trade (KIET). From 1986 to 1991, he worked at the bureau of trend analysis at KIET. In 1989 he was a visiting researcher at the Development Center at the OECD. That same year, Dr. Chang also worked at NISER in England as a visiting researcher. Since 1997, Dr. Chang has worked as a professional commissioner at the OECD. Since 1999, he has worked as a commissioner for the Regulatory Reform Committee under the President. Also, since 2001, he has worked as a commissioner for the Government Performance Evaluation Committee under the Prime Minister.

Dr. Chang taught Economics, International Trade and Theory of Public Industry Policy to students at Korea University, Soongshil University, Joongang University and The University of Seoul. In 1996, he held his Ph.D. from the Department of Economics at Northern Illinois University.