In order to be able potentially to make a normative value judgment and elaborate any common European standards with respect to the inclusiveness/exclusiveness of parties’ access to parliament, one must first clarify how inclusive/exclusive the different electoral systems across Europe actually are. However, the degree of inclusiveness/exclusiveness is dependent on several features, or mechanisms, which are either explicit or implicit components of these electoral systems. Since the same effect of excluding parties from parliament can be achieved through any of those, it would be insufficient, when measuring the degree of inclusiveness/exclusiveness, to focus solely on the legal threshold. Any contextual and sound comparative analysis of the issue would take into account also the mechanisms discussed above – the thresholds in the broader sense. At the same time, this brings significant difficulties. While all those mechanisms affect inclusiveness/exclusiveness of electoral systems, not all could be compared in a straightforward way. The analysis of the natural threshold showed, for instance, that this mechanism is not exactly the same as the nation-wide legal threshold. Yet, it is crucial for measuring the openness and cannot be, without jeopardizing sound conclusions, excluded from the analysis. It needs to be calculated for each member-state at the district as well as national level, and then the comparison of the issue of openness could perhaps proceed through these parallel and different routes until, ideally, estimations could at the end perhaps also be made as to the overall degree of openness. Crucially, none of these further steps could proceed without a detailed and in-depth political-science type of investigation into the issues.