In 1989 Norwegian economist Trygve Haavelmo was awarded the Nobel Prize “for his clarification of the probability theory foundations of econometrics and his analyses of simultaneous economic structures.” He made two main contributions in econometrics. The first is a 1943 article that shows some of the statistical implications of simultaneous equations. The second is a 1944 article that bases econometrics more firmly on probability theory.
During the war years Haavelmo worked for the Norwegian government in the United States. He was a professor of economics at the University of Oslo from 1948 until his retirement in 1979.