lsq {politicsR}

Least Squares Index

Description

'lsq()' calculates the electoral disproportionality between votes and seats by Least squares index method as proposed by Michael Gallagher.

Usage

lsq(x, y)

Arguments

x

(numeric). Numeric vector with the vote share of parties

y

(numeric). Numeric vector with the seat share of parties

Value

If the input is a proportion the result is between 0 and 1. But if the input is a percentage it is between 0 and 100. In both cases the higher the value, the more disproportional the electoral system is.

References

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

Examples

votes <- c(0.2, 0.2, 0.6)
seats <- c(0.18, 0.17, 0.65)
lsq(votes, seats)