volatility: Electoral Volatility

In albuja/electoral: Allocating Seats Methods and Party System Scores

Electoral Volatility

Description

Defined as the net change within the electoral party system resulting from individual vote transfers, electoral volatility is measured according to the following formula:

Volatility = sum|pi,t-1 - pi,t| / 2

in which pi,t is the vote/seat share for the party ith at a given election (t) and pi,t-1 is the vote/seat share of the same party ith at the previous elections (t-1) (Pedersen, 1979).

The index is a number from 0 to 1, 0 means no volatility (proportion of votes/seats remains constant for every party) and 1 means total volatility (every party pass from 0 to any votes or viceversa).

Developed by Jorge Albuja Delgado ([e-mail]).

Usage

volatility(votes_1, votes_2)

Arguments

votes_1	vector of number/share of votes/seats per party at time t-1 (previous election)
votes_2	vector of number/share of votes/seats per party at time t (given election

Value

A single numeric with volatility value in the interval [0, 1]

Examples

volatility(votes_1 = c(100, 150, 60),
           votes_2 = c(80, 120, 100))

albuja/electoral documentation built on Feb. 7, 2023, 5:12 a.m.