This article recalls the most recent trends in territorial differentiation which have emerged in United Kingdom, Spain and Italy, arguing that one of the central facets that have contributed to the growth in centrifugal drives within these states is the lack of a territorial upper house that engages sub-state tiers of government in the law-making procedure, so that they may have their say in national decisions affecting their territorial interests. This argument is still unproven, since no methodology has been provided so far in order to demonstrate the relationship between a push toward independence and the absence of a federal chamber. Against this background, the article is a first attempt to shed light on such a relationship, as it seeks to set the stage to understanding how to build a possible methodology.