“…Research has been particularly concerned to search for evidence of the cartel party thesis proposed by Katz and Mair (1995), investigating the effects of financial support to political parties on patterns of party competition (Scarrow 2006(Scarrow , 2007, party entry (Tavits 2007;van Biezen & Rashkova 2012), party membership (Casas-Zamora 2005; Whiteley 2011), party system change (Pierre, Svåsand & Widfeldt 2000), and institutionalisation (Booth & Robbins 2010). Results have so far revealed little evidence that party regulation, alone, affects party systems, nor have led to any generalisable conclusions (Koss 2008). Scholars have underlined the difficulty of insulating the effects of party regulation vis-à-vis other institutional and non-institutional factors, such as electoral rules or changes in public opinion (Casas-Zamora 2005;Pierre, Svåsand & Widfeldt 2000;Scarrow 2006;.…”