tbi {politicsR}

T Imbalance Index

Description

'tbi()' calculates T index of inbalance according to the proposition of Taagepera (1979).

Usage

tbi(x)

Arguments

x

(numeric). A number vector with share of votes or seats. The vector should range from 0 to 1 (if not, the function will automatically make the vector elements sum to one).

Value

The index ranges from 0 to 1, with 0 being total equilibrium, and 1 total imbalance. When used as an indicator of competitiveness, 0 is the scenario of total competitiveness and 1 is a scenario dominated by one or a few competitors.

References

Taagepera, R. (1979). Inequality, Concentration, Imbalance. Political Methodology, 6(3), 275–291. http://www.jstor.org/stable/25791080

Examples

tbi(c(0.2, 0.3, 0.5))