Replication data for: The Coefficient of Party Influence

In a 2000 article in American Journal of Political Science, James Snyder and Tim Groseclose develop and apply an innovative method for detecting and estimating the frequency and magnitude of party influence in congressional roll call voting. This paper presents a framework for assessing the coefficient that the authors interpret as "party influence." The analysis reveals that, and shows why, the coefficient manifests two troublesome characteristics. The coefficient cannot discriminate between disparate types of party influence because the mapping between types of partison influence and signs of the coefficient is not one-to-one. Similarly, the coefficient has a responsiveness problem because a marginal increase in one party's influence can cause the estimate of the coefficient to increase, decrease, or remain constant. Because the literature on parties in Congress emphasizes majority-party strength, the inability of the coefficient to isolate party-specific effects is a serious drawback in the ongoing hunt for genuine party discipline.2000年发表于《美国政治科学杂志》（American Journal of Political Science）的一篇论文中，詹姆斯·斯奈德（James Snyder）与蒂姆·格罗斯克洛斯（Tim Groseclose）提出并应用了一种创新方法，用于检测国会唱名投票中政党影响力的发生频率与影响程度，并对其进行量化估算。本文则构建了一套分析框架，用于评估上述研究中被两位作者阐释为"政党影响力"的系数。分析结果表明，该系数存在两处令人困扰的特性，并揭示了其内在成因：其一，该系数无法区分不同类型的政党影响力，原因在于不同类型的政党影响力与系数符号之间并非一一对应的映射关系；其二，该系数存在响应性缺陷——某一政党影响力的边际提升，可能导致该系数的估算值上升、下降或保持不变。鉴于国会政党研究领域的文献均聚焦于多数党实力，因此在探寻真正政党纪律的持续研究中，该系数无法分离出政党专属效应这一局限，无疑是一项严重的缺陷。