In almost all subfields of political science in the last third of the twentieth century, it was claimed that we are witnessing a transformation of political order from hierarchies to networks. This paper traces institutional change during the twentieth century by examining structures and modes of interaction in transboundary regions in Europe and North America. First, it challenges functionalist explanations of institution-building and institutional change. Instead, the impact of general discourses and ideas is highlighted. Second, it takes a closer look at the hierarchies-to-networks transformation thesis. Whereas this thesis can be confirmed if we define hierarchies and networks as patterns of interaction, if we define hierarchies and networks in terms of modes of interaction this is less certain. De jure, institutional elements implying a "hierarchical order" have been supplanted in newer institutions by provisions allowing for "majority voting." De facto, nothing has changed, since these modes of interaction have never actually been used. In practice, the only way to achieve joint action has always been and still is through "agreement" or "consent." What has changed over the years, though, is the institutionalized approach to reaching "agreement." The older approach uses a technocratic-deductive logic. In recent years, we have been able to observe various new approaches in cross-border regions: a symbolic-inductive logic in Western Europe, a utilitarian-evolutionary logic along the U.S.-Mexican border, and a normative-constructivist logic along the U.S.-Canadian border. Based on the empirical findings, I conclude that institutional theory should pay more attention to the fact that many political institutions provide orientation, shape identities, and mobilize activities through emotional symbols