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During World War I he was a military in the German army. In 1918 he joined the German Democratic Party (Deutsche Demokratische Partei). Between the wars he worked as an economist and professor on the Technical University of Berlin.
After World War II he co-founded the Liberal Democratic Party of Germany (LDPD) in the Soviet Occupied Zone (SBZ). In 1945 he was briefly the Chairman of the LDPD, but the Soviets forced him to resign after a few months. He opposed the land reform plans of the Soviet authorities and the Socialist Unity Party (SED).
Until 1948 Koch was a member of the LDPD's executive committee.
In 1949 he went to West Germany (West Berlin) and again worked as an economist professor. From 1955 he worked as professor at the University of Nuremberg. From 1948 to 1956 Koch was a member of the liberal FDP (Free Democratic Party).
|Chairman of the Liberal Democratic Party of Germany