Replication data for: The Geometry of Multidimensional Quadratic Utility in Models of Parliamentary Roll Call Voting

The purpose of this paper is to show how the geometry of the quadratic utility function in the standard spatial model of choice can be exploited to estimate a model of parliamentary roll call voting. In a standard spatial model of parliamentary roll call voting, the legislator votes for the policy outcome corresponding to Yea if her utility for Yea is greater than her utility for Nay. The voting decision of the legislator is modeled as a function of the difference between these two utilities. With quadratic utility, this difference has a simple geometric interpretation that can be exploited to estimate legislator ideal points and roll call parameters in a standard framework where the stochastic portion of the utility function is normally distributed. The geometry is almost identical to that used by Poole (2000) to develop a nonparametric unfolding of binary choice data and the algorithms developed by Poole (2000) can be easily modified to implement the standard maximum-likelihood model.

本文旨在阐释，如何借助标准空间选择模型（spatial model of choice）中的二次效用函数（quadratic utility function）的几何特性，对议会点名投票模型进行估计。在标准的议会点名投票空间选择模型中，当议员对投赞成票（Yea）的效用高于投反对票（Nay）的效用时，其会选择对应政策结果的赞成票。议员的投票决策被建模为这两种效用之差的函数。在二次效用函数的设定下，该效用差具备简洁的几何解释，可用于在效用函数随机项服从正态分布的标准框架下，估计议员理想点（legislator ideal points）与点名投票参数。该几何方法与普尔（Poole, 2000）用于构建二元选择数据非参数展开（nonparametric unfolding）的几何方法几乎完全一致，且普尔（2000）提出的算法可经简单修改后，用于实现标准最大似然模型（maximum-likelihood model）。