His research and teaching interests span the topics of federalism, territorial politics, methodology, regional government, regional elections, multilevel governance, and regionalist parties. Arjan is the author of journal articles that have appeared in various journals such as Acta Politica, Comparative Political Studies, Governance, Regional Studies, and Regional and Federal Studies. In addition Arjan has published books with Routledge (The Rise of Regional Authority: A Comparative Study of 42 Countries, with Liesbet Hooghe and Gary Marks, Routledge, 2010) and Palgrave Macmillan (Regional and National Elections in Western Europe. Territoriality of the Vote in Thirteen Countries, edited with Regis Dandoy, forthcoming).