“…These variables are often considered as important factors for explaining citizens' political attitudes. Specifically, previous studies show that party membership and political efficacy are strongly associated with age, gender, education, political trust, political interest, as well as citizenship norms (Dahlberg et al, 2015;Fatke, 2014;Hooghe and Kölln, 2020;Magalhães, 2014;Strömbäck et al, 2013;Van Biezen et al, 2012;Whiteley, 2011). To consider the cross-country differences in political institutions and government performance and contextual backgrounds, we include several country-level variables as control variables: government quality (Government), gross domestic product per capita calculated by purchasing power parity (GDP), unemployment rate (U), the legal provision of direct democracy (Dem), the frequency of direct democracy used in making political decisions (Dem2), and party system fragmentation (Fragment).…”