Comparison of electoral systems

Electoral systems are the rules for conducting elections, a main component of which is the algorithm for determining the winner (or several winners) from the ballots cast. This article discusses the justifications which have been offered for different algorithms, both those which elect a unique candidate from a 'single-winner' election and those which elect a group of representatives from a multiwinner election. The choice between the two types of election is a political question not discussed here.

A panel of 22 experts on voting procedures were asked in 2010 to say which of 18 representative single-winner voting methods they endorsed. One member abstained. The ranking (with number N of approvers from a maximum of 21) of the various systems was as follows.[1]

methodN methodN
1Approval voting15 10Black's method3
2Alternative vote (IRV)10 11=Range voting2
3Copeland's method9 Nanson's method2
4Kemeny–Young method8 13=Leximin method1
5=Two-round system6 Smith's method1
Coombs' method6 Uncovered set method1
7=Minimax5 16=Fishburn's method
Majority judgement5 Untrapped set
9Borda count4 FPTP