enp: The Effective Number of Parties Index

In politicsR: Calculating Political System Metrics

The Effective Number of Parties Index

Description

'enp()' calculates the number of Effective Political Parties according to the formula proposed by Laakso and Taagepera (1979).

Usage

enp(x)

Arguments

x	(numeric). A numeric vector in the form of a proportion of votes or seats. The vector should between from 0 to 1.

Value

A value corresponding to the number of effective parties. Normally we deprecate the fraction in the analysis, leaving only the integer.

References

Laakso, M., & Taagepera, R. (1979). “Effective” Number of Parties: A Measure with Application to West Europe. Comparative Political Studies, 12(1), 3–27. https://doi.org/10.1177/001041407901200101

Examples

 enp(c(0.2, 0.3, 0.5))

politicsR documentation built on March 31, 2023, 10:10 p.m.