VoteFair representation ranking: Difference between revisions
Clarified differences between STV version and default version
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(Clarified differences between STV version and default version) |
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'''VoteFair representation ranking''' is a [[Proportional representation|Proportional-representation]] (PR) vote-counting method that uses [[Preferential voting|ranked ballots]] and selects a candidate to win the second seat in a two-seat legislative district. The second-seat winner represents the voters who are not well-represented by the first-seat winner. Any single-winner election method that uses ranked ballots and [[Pairwise counting|pairwise counting]] can be used for the popularity calculations.
This method can be repeated to fill additional seats. For this purpose the STV version would be used for non-partisan elections, such as electing members of a city council. The default (non-STV) version assumes that other elections in the same region still use plurality voting and therefore causes politics to be dominated by two large political parties.
== Description ==
This method first identifies which voters are well-represented by the first-seat winner. Then a reduced influence is calculated for these ballots. Their influence is determined by the extent to which they exceed the 50% majority minimum that is needed to elect the first-seat winner. The remaining ballots have full influence. Using these adjusted influence levels, the most popular of the remaining candidates becomes the second-seat winner.
This method ignores which political party each candidate is in, yet the
== Calculation steps ==
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## The result is the fraction of a vote that is allowed for each ballot identified in step 4.
# Based on all the ballots, but with reduced influence for the ballots identified in step 4, identify the most popular candidate from among the remaining candidates. This candidate becomes the second-seat winner.
== STV version ==
This calculation method can be extended to fill multiple seats. This usage produces proportional results such as achieved when using the Single Transferable Vote (STV). Unlike STV this method provides better protection against tactical voting.
For these purposes:
* Use the method described above to fill the first two seats.
* In step 1, the ballots to be ignored include any ballot on which any of the already-elected candidates appear at the top preference level.
* In step 5-2 the word ''half'' is changed to ''two-thirds'' when filling the third seat, ''three-fourths'' when filling the fourth seat, ''four-fifths'' when filling the fifth seat, and so on.
* When filling the third seat, a ballot is given zero influence if that ballot ranks both of the already-elected candidates higher than the candidate identified in step 1. Similarly, when filling the fourth and fifth seats, a ballot is given zero influence if that ballot ranks all three or four (respectively) of the already-elected candidates higher than the candidate identified in step 1. For this purpose, if a ballot ranks a not-yet-elected candidate at the same preference level as an already-elected candidate then that ballot is given zero influence during steps 4 and 5.
== Example ==
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