He was born in Oslo and graduated as cand.oecon. in 1954. He worked in Statistics Norway from 1955 to 1970, and was hired as a deputy under-secretary of state in the Ministry of Finance in 1971. He kept this job until 1978, when he became advisor of economical matters. From 1980 to 1990 he was the director of Statistics Norway. He was then permanent under-secretary of state in the Ministry of Finance (finansråd) from 1990 to 1995.[2]
Øien was a member of the board of Arbeiderbladet from 1981 to 1986 and Oslo Sporveier from 1996 to his death, the last two years as deputy board chairman.[2]