His studies on Rome were particularly concerned with rural life in the later period of the empire, a subject upon which he wrote widely. Gummerus' doctoral dissertationDer römische Gutsbetrieb als wirtschaftlicher Organismus nach den Werken des Cato, Varro und Columella examined large Roman estates using mainly literary sources. He further examined the economic system of the Roman empire in an article published in the Pauly–Wissowa classical encyclopedia, this time systematically using Archeological artifacts in his study. Gummerus' technique predated the work of Michael Rostovtzeff by a decade.
Political
An early advocate of Finnish independence, Gummerus was imprisoned for this in 1904, spending time in Peter and Paul Fortress. He went on to edit the journal Framtid and before forming the anti-Russification Wetterhof Bureau in Germany in 1915. After independence had been achieved Gummerus was appointed to posts in Stockholm and Kiev, where he had extended his anti-Russian activity and where he helped set up a legation during Ukraine's brief independence. He became Envoy to Rome in 1920 and developed an admiration for the growing fascist movement whilst in Italy. On his return to Finland, and with the leaders of the Lapua Movement mostly imprisoned, he joined with Erkki Räikkönen, a fellow Swedish-speaker, and Vilho Annala to form IKL as a slightly more moderate continuation. Driven by an inherent conservatism, Gummerus desired an electoral alliance with the National Coalition Party but soon found that the rank and file of IKL had no interest in this. IKL also adopted a strong position on the importance of the Finnish language, following the lead of the Academic Karelia Society and further isolating the Swedish-speaking Gummerus. He finally left the movement in 1934 and took no further role in active politics. Despite his linguistic identity Gummerus went on to criticize Sweden, attacking the Blue Book of former Swedish foreign ministerJohannes Hellner, which claimed that Sweden had only been interested in cultivating Finland as a good neighbour in the Åland crisis. Gummerus argued that, whilst this may have been the case, Swedish attitudes towards the newly independent country where such that a state of mistrust and suspicion was engendered between the two countries.
