In 1920 Geiger joined the Social Democratic Party of Germany (SPD). In the same year he became an assistant at the "Statistischer Reichsamt", the statistics office, in Munich, working in the trade statistics department from 1924 to 1933. His home, however, was in Berlin, where he published the magazine "Fremde Presse" (Foreign Press), with news on the "Reich" ministry for the army from 1920 - 1929. At the same time he edited the information magazine of the newly founded Berlin "Volkshochschule" (adult education centre) where he had begun to work as a teacher.