Gallagher Index
Example of calculating disproportionality
Columns: party | % of votes | % of seats | difference | difference squared
Labour | 41.10 | 41.32 | 0.22 | 0.0484 | National | 39.10 | 39.67 | 0.57 | 0.3249 | NZ First | 5.72 | 5.79 | 0.07 | 0.0049 | Greens | 5.30 | 4.96 | 0.34 | 0.1156 | Māori | 2.12 | 3.30 | 1.18 | 1.3924 | United Future | 2.67 | 2.48 | 0.19 | 0.0361 | ACT | 1.51 | 1.65 | 0.14 | 0.0196 | Progressives | 1.16 | 0.82 | 0.34 | 0.1156 | Destiny | 0.62 | 0 | 0.62 | 0.3844 | Legalise Cannabis | 0.25 | 0 | 0.25 | 0.0625 | Christian Heritage | 0.12 | 0 | 0.12 | 0.0144 | Alliance | 0.07 | 0 | 0.07 | 0.0049 | Family Rights | 0.05 | 0 | 0.05 | 0.0025 | Democrats | 0.05 | 0 | 0.05 | 0.0025 | Libertarianz | 0.04 | 0 | 0.04 | 0.0016 | Direct Democracy | 0.03 | 0 | 0.04 | 0.0016 | 99MP | 0.03 | 0 | 0.03 | 0.0009 | OneNZ | 0.02 | 0 | 0.02 | 0.0004 | Republicans | 0.02 | 0 | 0.02 | 0.0004 | total of squares of differences | total of squares of differences | total of squares of differences | total of squares of differences | 2.5336 | total / 2 | total / 2 | total / 2 | total / 2 | 1.2668 | square root of (total / 2) | square root of (total / 2) | square root of (total / 2) | square root of (total / 2) | 1.13