# volatility: Electoral Volatility In electoral: Allocating Seats Methods and Party System Scores

## 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 ([email protected]).

## Usage

 `1` ```volatility(votes_1, votes_2) ```

## Arguments

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

## Value

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

## Examples

 ```1 2``` ```volatility(votes_1 = c(100, 150, 60), votes_2 = c(80, 120, 100)) ```

electoral documentation built on Oct. 25, 2018, 9:06 a.m.