10.7910/DVN/KYVPKZ Nemčok, Miroslav Miroslav Nemčok https://orcid.org/0000-0003-3556-5557 Masaryk University Harvard Dataverse 2020 Social Sciences Nemčok, Miroslav Miroslav Nemčok University of Helsinki 2020-03-31 2020-03-31 10.7910/DVN/KYVPKZ/APJQLN 10.7910/DVN/KYVPKZ/23TVJG 10.7910/DVN/KYVPKZ/LYQHQR 306736 47156 79095 text/tab-separated-values type/x-r-syntax text/tab-separated-values 1.0 Creative Commons CC0 1.0 Universal Public Domain Dedication. Parties can not only actively adjust the electoral rules to reach more favourable outcomes, as is most often recognized in political science, but they also passively create an environment that systematically influences electoral competition. This link is theorized and included in the wider framework capturing the mutual dependence of electoral systems and party systems. The impact of passive influence is successfully tested on one out of two factors closely related to party systems: choice set size (i.e., number of options provided to voters) and degree of ideological polarization. The research utilizes established datasets (i.e., Constituency-Level Elections Archive, Party System Polarization Index, Chapel Hill Expert Survey, and Manifesto Project Database) and via regression analysis with clustered robust standard errors concludes that the choice set size constitutes an attribute with passive influence over electoral systems. Thus, it must be reflected when outcomes of electoral systems are estimated or compared across various contexts.