Rokkan received many awards. He was a foreign honorary member of the American Academy of Arts and Sciences, a foreign associate of the National Academy of Sciences of the United States, an international member of the American Philosophical Society, and a member of the Finnish and Norwegian Academies of Sciences. He received honorary degrees from the University of Uppsala in 1970, the University of Helsinki in 1971, and the University of Geneva and the University of Aarhus in 1979. Rokkan's work "Norway: Numerical Democracy and Corporate Pluralism" (1966) was selected for the Norwegian Sociology Canon in 2009–2011 as one of 25 works that "had the greatest influence on sociology in Norway."Norwegian Sociology Canon Academic research After focusing on individual voters, he turned his attention to the study of politics, especially the formation of political parties and European nation-states. Peter Flora's overview of Rokkan's oeuvre points out that the "unity of Rokkan work stems from his constant concern with the European nation-state and its democratization." "Cleavage Structures, Party Systems, and Voter Alignments" In this 1967 co-authored work with Seymour Martin Lipset, Rokkan introduced critical juncture theory and made a substantial contributions to cleavage theory. Peter Flora notes that the "initial analysis of the origins of cleavage structures and their transformation into party systems appeared in 1965 ... in German" in a version that "carried Rokkan's name alone." Seymour Lipset and Stein Rokkan (1967) and Rokkan (1970) introduced the idea that big discontinuous changes, such as the reformation, the building of nations, and the industrial revolution, reflected conflicts organized around social cleavages, such as the center-periphery, state-church, land-industry, and owner-worker cleavages. In turn, these big discontinuous changes could be seen as critical junctures because they generated social outcomes that subsequently remained "frozen" for extensive periods of time. In more general terms, Lipset and Rokkan's model has three components: (1) Cleavage. Strong and enduring conflicts that polarize a political system. Four such cleavages were identified: The center–periphery cleavage, a conflict between a central nation-building culture and ethnically linguistically distinct subject populations in the peripheries. The state–church cleavage, a conflict between the aspirations of a nation-state and the church. The land–industry cleavage, a conflict between landed interests and commercial/industrial entrepreneurs. The worker–employer cleavage, a conflict between owners and workers. (2) Critical juncture. Radical changes regarding these cleavages happen at certain moments. (3) Legacy. Once these changes occur, their effect endures for some time afterwards.