Complex sentence: In 1964, he was appointed Professor in the Department of Economics and Commerce at Simon Fraser University, serving as founding Head of the deparment until 1969 and as Chairman from 1972 to 1975.
Split into simpler sentences: In 1964, he was appointed Professor in the Department of Economics at Simon Fraser University. From 1964 to 1969, he was Head of the deparment and Chairman from 1972 to 1975.