SciencesPo (version 1.3.6)

gallagher: Gallagher index

Description

Calculates the Gallagher index of LSq index.

Usage

gallagher(v, s)

Arguments

v

A vector containing the votes for each political party.

s

A vector containing the election outcome as seats.

Value

• The Gallagher's Representation Score.

Details

The representation score is calculated as: sqrt(sum((Z-R)^2)/2).

References

Gallagher, M. (1991) Proportionality, disproportionality and electoral systems. Electoral Studies 10(1):33-51.

Examples

# 2005 UK General Election
pvotes = c(Lab=35.20, Cons=32.40, Lib=22, DUP=0.90,
SNP=1.50, Sinn.Fein=0.60, Plaid=0.60, SDLP=0.50, UUP=0.50,
Ind=0.50, Respect=0.30, Health=0.10, Speaker=0.10, Others=4.80)
seats = c(385,198, 62, 9,6,5,3,3,1,1,1,1,1,0)/676

# 2012 Queensland state elecion
pvotes= c(49.65, 26.66, 11.5, 7.53, 3.16, 1.47)
pseats = c(87.64, 7.87, 2.25, 0.00, 2.25, 0.00)

gallagher(pvotes, pseats)