Spatial Models of Parliamentary Voting (Analytical Methods for Social Research) by Keith T. Poole

Analytical Methods for Social Research

by Keith T. Poole

This book presents a simple geometric model of voting as a tool to analyze parliamentary roll call data. Each legislator is represented by one point, and each roll call is represented by two points that correspond to the policy consequences of voting Yea or Nay. On every roll call each legislator votes for the closer outcome point, at least probabilistically. These points form a spatial map that summarizes the roll calls. In this sense a spatial map is much like a road map in that it visually depicts the political world of a legislature. The closeness of two legislators on the map shows how similar their voting records are, and the distribution of legislators shows what the dimensions of the space are. These maps can be used to study a wide variety of topics, including how political parties evolve over time, the existence of sophisticated voting, the representation of ethnic minorities in the legislature, constituency interests and legislative behavior, and how an executive influences legislative outcomes.

Paperback

First published June 15, 2001