volatility {politicsR}

Electoral Volatility Index

Description

'volatility()' calculates electoral volatility index developed by Perdersen (1979).

Usage

volatility(x, y)

Arguments

x

(numeric). Numeric vector with the vote share for selected parties in a given election in t.

y

(numeric). Numeric vector with the vote share for selected parties in the t+1 election.

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 volatile is the electoral system.

References

Pedersen, M. N. (1979). The dynamics of European party systems: changing patterns of electoral volatility. European journal of political research, 7(1), 1-26.

Examples

x <- c(0.3, 0.7)
y <- c(0.5, 0.5)
volatility(x, y)