Replication Data for: Political Institutions, Electoral Systems, and Party Stability in 40 Democracies Including Brazil

This article investigates the impact of political and electoral institutions on party system stability in 40 democracies, including Brazil. Party stability is analyzed using the Electoral Party Variation (EPV) indicator, based on the Effective Number of Electoral Parties (ENEP). The political and electoral institutions of interest include electoral magnitude, electoral formula, and an approach derived from Sartori (strong, feeble, and moderate electoral systems). The analysis employs four models using the generalized estimating equation (GEE) method for panel data (40 cases, seven periods). It is observed that the electoral system is efficient in explaining party stability. High average district magnitude, proportional electoral formula, and feeble electoral systems are permissive factors for party system instability. The case of Brazil is not an exception, as the instability of the party system in the country is appropriately interpreted in light of the prevailing political institutions.本文考察了包括巴西在内的40个民主国家中，政治与选举制度对政党制度稳定性的影响。本研究基于有效选举政党数（Effective Number of Electoral Parties, ENEP）构建选举政党变动（Electoral Party Variation, EPV）指标，并以此对政党稳定性展开分析。本次研究关注的政治与选举制度维度涵盖选举规模、选举公式，以及源自萨托里（Sartori）的选举制度分类方法（即强、弱与温和选举制度）。本分析针对面板数据（共40个样本、7个观测周期），采用广义估计方程（generalized estimating equation, GEE）方法构建了四组模型。研究结果表明，选举制度能够有效解释政党制度的稳定性差异：较高的平均选区规模、比例代表选举公式，以及弱选举制度，均为助长政党制度不稳定的宽松条件。巴西案例亦非特例，该国政党制度的不稳定状况可结合其现行政治制度得到合理解释。