ABSTRACT

Theoretical and empirical models of congressional voting assume that legislators vote with the sole purpose to move policy closer to their ideologically ideal point. While NOMINATE correctly classifies most votes cast by members of Congress, a significant number of votes are misclassified and coded as spatial error. The literature on congressional voting assumes this error to be random and idiosyncratic across members. We argue that spatial errors are systematic across members, with spatial error being more likely on roll-call votes tackling salient policy issues and among members representing constituencies with greater ideological divergence between the median voter and the member's primary election constituency. Using Aldrich-McKelvey scaling to place legislators and constituencies in the same ideological space, we find support for our theory. We attribute this finding to the electoral uncertainty faced by members of both the House and Senate representing constituencies with greater ideological divergence between these key electoral principals.

摘要

国会投票的理论和实证模型假设立法者投票的唯一目的是使政策更接近他们的意识形态理想点。虽然 NOMINATE 正确分类了国会议员投出的大多数选票，但仍有大量选票被错误分类并编码为空间错误。关于国会投票的文献假设这个错误是随机的，并且在成员之间是特殊的。我们认为，空间错误在成员之间是系统性的，空间错误更可能出现在解决突出政策问题的唱名投票中，以及代表选民中间选民和成员的主要选举选区之间意识形态分歧更大的选区的成员之间。使用 Aldrich-McKelvey 缩放将立法者和选区置于同一意识形态空间，我们找到了对我们理论的支持。我们将这一发现归因于代表选区的众议院和参议院成员面临的选举不确定性，这些关键选举负责人之间存在更大的意识形态分歧。