Karhunen received his master's degree in 1938 and his doctorate in 1950 from the University of Helsinki. The topic of his thesis was (in German) Über lineare Methoden in der Wahrscheinlichkeitsrechnung,[2] in English On linear methods in probability and statistics. The advisor of his thesis was the mathematician Rolf Nevanlinna.[3]
Karhunen worked as a lecturer at the University of Helsinki before leaving the academic world to be employed by the insurance corporation Suomi, becoming CEO of the company in 1963.[citation needed]
Karhunen served in 1955 on the Finnish Committee for Mathematical Machines, which developed the first Finnish computer ESKO.[4]