“…This outcome, in turn, if occurring consistently over time, can lead to party system de-institutionalization (Chiaramonte and Emanuele, 2015), a situation which -as we have learned from the Eastern European (Birch, 2003;Powell and Tucker, 2014;Sikk, 2005) and Latin American (Mainwaring and Scully, 1995) experience -may affect the democratic process, both in terms of its legitimacy and its effectiveness. Indeed, recent studies have pointed out that new party entry causes the reduction in voter turnout levels (Robbins and Hunter, 2011) and increases uncertainty both in the voting decision-making (Ezrow, Homola and Tavits, 2014;Marinova, 2016) and in the process of government formation (Grotz and Weber, 2015), thus weakening accountability. In the context of Western Europe, new parties have been studied so far mainly from the traditional party-level perspective, by focusing on their ideologies, political platforms, organisations (Hug, 2001;Kitschelt, 1988;1995;Lucardie, 2000;Willey, 1998).…”