Fit for parliament: a new index of electability, assessing the electoral success of group-based parties

The openness of the political system for the representation of social or economic groups through their parties is mired in complexities. Extant scholarship has identified multiple electoral system hurdles that jointly determine the institutional opportunities for group representation: This article offers a simple metric to the institutional parts of the political opportunity structure for the electoral representation of social groups. A single variable summarizes the institutional opportunities for group representation, as determined jointly by electoral rules, the demographic structure of ethnic minority groups and their electoral geography. This new Index of Electability considers recent innovations in electoral rules, such as mixed electoral systems, legal thresholds or quotas, which occur in most contemporary democracies. Empirically, the index is applied to ethnic minority parties in 57 plural democracies worldwide. It shows that our index highlights the necessary conditions for parliamentary representation of minorities through their own parties. Contrary to widespread belief that many minority groups form ethnic parties, only one out of three ethnic minority groups worldwide which could, in principle, do so, actually form such a party.

借助政党实现社会或经济群体代表权的政治体系开放性，深陷复杂纠葛之中。现有学术研究已识别出多重选举制度障碍，这些障碍共同决定了群体代表权的制度性机遇：本文针对社会群体选举代表的政治机遇结构之制度维度，提出了一项简便量化指标。该单一变量可综合体现群体代表权的制度性机遇，而这一机遇由选举规则、少数族裔群体的人口结构及其选举地理格局共同决定。这一全新的选举可及性指数（Index of Electability）纳入了当代多数民主国家普遍采用的选举规则创新举措，例如混合选举制、法定参选门槛或席位配额等。在实证层面，本指数被应用于全球57个多元民主国家的少数族裔政党。研究结果表明，本指数明确了少数族裔通过自身政党实现议会代表权的必要条件。与诸多认为多数少数族裔群体都会组建族裔政党的普遍认知相悖，全球范围内原则上具备组建族裔政党条件的少数族裔群体中，仅有三分之一真正组建了此类政党。