Types of multilevel systems and new party entry: Assessing the impact of institutional opportunity structures

Despite the federal-unitary divide being a classical distinction in the comparative analysis of political systems, we find little comparative research on how central institutional differences between multilevel systems defined by several directly elected governmental tiers affect the extent to which parties can exploit the presence of such tiers as an opportunity structure to their own advantage. This is surprising especially in the EU context which provides the unique opportunity to compare party strategic behaviour across a variety of multilevel systems all composed of three directly elected tiers (regional-national-EU) that also differ in constitutional status and competence of regional governments (regional autonomy), and the length of time a second or third elected tier has been established in the respective system. To close this gap, we first theorize the implications of these institutional aspects for parties’ decision to run elections on another level, hence to expand their representational reach across tiers, after their parliamentary breakthrough. We analyze these critical decisions made by 211 parties in 13 three-tiered multi-level systems in Europe from 2004-2023 showing that institutional differences matter. Holding party characteristics constant, parties’ propensity of running elections beyond their initial parliamentary entry level varies across constitutional status and regional autonomy, but not on the length of time a second or third elected tier has been established in multilevel systems. While stronger regional autonomy discourages parties from contesting elections beyond their initial parliamentary entry level, irrespective of their entry level, parties operating in federalized systems are more incentivized to compete on other tiers.