Since Rokkan, local party system nationalization is predominantly considered as a uniform end state of party politicization. However, the endurance of non-national electoral forces serves as empirical counterweight to this teleology. In this vein, scholars emphasize most of such party systems mix local (i.e. place-bound lists and/or independent candidates) with national (i.e. local chapters of national parties) elements studying what predominates the blend. This paper argues for a more fine-grained approach to the default local-national dichotomy. It assumes the local flag covers a variegated load of area-specific phenomena. Based on a typology of vertical autonomy, the morphology of the local party system is firstly discerned as comprised of national, pseudo-national, pseudo-local and independent local lists. Subsequently, this underpins a refined index applied to describe contemporary local party system nationalization in Belgium. The paper will finally study the explanatory power of institutional, political and cultural factors for variation in the index.
