Disproportionality often cannot range from zero to one: a note on the Gallagher index and a new normalised measure
Published online on June 02, 2026
Abstract
Party Politics, Ahead of Print.
The Gallagher index is the most popular measure of disproportionality in political science. While many assume that it can range from 0 (perfect proportionality) to 1 (perfect disproportionality), I prove that its maximum value is constrained by the size ...
The Gallagher index is the most popular measure of disproportionality in political science. While many assume that it can range from 0 (perfect proportionality) to 1 (perfect disproportionality), I prove that its maximum value is constrained by the size ...