Replication Data for: The Activists Who Divide Us: A Cross-Country Analysis of Party Activists’ Influence on Polarization and Representation

What explains party polarization in multiparty systems? This study turns the spotlight to intraparty mechanisms, namely, the authorities and influence of party activists over the candidate selection process, as a potential source of party-system polarization. I hypothesize that parties in which activists possess more comprehensive selection authorities, the party elite will hold more extreme ideological positions, catering to activists' representation demands. Additionally, in such cases, the ideological gap between party elites and voters will be larger since more extreme actors overshadow the preferences of moderate party voters. Aggregating the intraparty effect of activists to the party-system level, I expect to find higher level of party polarization in countries where more parties allocate selection authorities to activists. Utilizing party-level data regarding candidate selection procedures as well as public opinion and elite position data from 19 countries and 93 parties between 2011-2017, I find support for my hypotheses.多党制（multiparty systems）下的政党极化（party polarization）何以形成？本研究将目光投向党内机制（intraparty mechanisms）——即政党积极分子（party activists）在候选人遴选流程（candidate selection process）中所拥有的权限与影响力——将其视为政党体系极化（party-system polarization）的潜在诱因。本研究提出假说：当政党积极分子拥有更全面的遴选权限时，该政党的政党精英（party elite）将持有更为极端的意识形态立场，以迎合积极分子的代表诉求。此外，在此类情境下，政党精英与选民之间的意识形态鸿沟将更为显著，因为极端立场的参与者会掩盖温和派政党选民的偏好。将积极分子的党内效应聚合至政党体系层面后，本研究预期：在更多政党将遴选权限赋予积极分子的国家中，政党体系极化程度更高。本研究利用2011年至2017年间覆盖19个国家、93个政党的候选人遴选流程政党层面数据，以及公众舆论与精英立场数据，验证了所提出的全部假说。