SciencesPo (version 1.3.8)

grofman: Grofman index

Description

Calculates the Grofman index of proportionality based on a vector of votes and a vector for the electoral outcome.

Usage

grofman(v, s)

Arguments

v

A vector containing the votes for each political party.

s

A vector containing the election outcome as seats.

Value

• A single score given the vector of votes and the vector for seats.

References

Taagepera, R., and B. Grofman. Mapping the indices of seats-votes disproportionality and inter-election volatility. Party Politics 9, no. 6 (2003): 659-77.

Examples

# 2012 Quebec provincial election:
pvotes = c(PQ=31.95, Lib=31.20, CAQ=27.05,QS=6.03,Option=1.89, Other=1.88)
pseats = c(PQ=54, Lib=50, CAQ=19, QS=2, Option=0, Other=0)

grofman(pvotes, pseats)