SciencesPo (version 0.11.21)

get.ipc: Computes the Intra-party Competition Index

Description

Intra-party competition is given by: $$ipc = \frac{(2 * N)}{(Magnitude - 1)}$$

Usage

get.ipc(n, mag = NULL)

Arguments

n

is a value or a vector with the number of candidates for a party within districts.

mag

is the district magnitude or a vector containing district magnitudes.

Value

• Either a numeric value or a vector with the IPC for each observation.

encoding

UTF-8

Details

Normatively, it is necessary two times the number of candidates out the size of the district to generate electoral competitiveness. When it comes to the party level in PR systems, one might want to apply the same reasoning but also within a party. Then, the higher the IPC found, the higher the intra-party competition for a given party.

Examples

# First example: generate some raw data

data <- data.frame( 
	i=i <- rep(1, len = 100),
	t=t<-sample(c("2008", "2012"), 100, replace=TRUE),
	p=p <- sample(LETTERS[1:3], 100, replace=TRUE),
	j=j <- sample(letters[1:13], 100, replace=TRUE) )

## IPC for each party nested within districts over time.

data$tcan = with(data, ave(i, t, p, j, FUN = sum))

get.ipc(data$tcan, mag = 2)

# Second example: generate some aggregate data

data2 <- data.frame( 
	a_i=i <- rep(1:5, c(1, 1, 4, 4, 3)),
	t=t<-sample(c("2008", "2012"), 13, replace=TRUE),
	p=p <- sample(LETTERS[1:3], 13, replace=TRUE),
	j=j <- sample(letters[1:13], 13, replace=FALSE) )

## IPC for each party nested with districts and over time.

get.ipc(data2$a_i, mag = 1)