On the Parameters of Uniform Swing in Single-Member Constituency Electoral Systems

Abstract

The concept of uniform swing across a set of constituencies is widely used in analyses of British general election results. The uniformity of swing is paradoxical, since only in very special cases will it be the result of a uniform national process. The present paper investigates that paradox, and identifies the spatially varying parameters of electoral change needed to produce uniform swing. Further, it adapts the entropy-maximising procedures to provide best estimates of interconstituency variations in changing voter preferences between elections.