User:RalphInOttawa/Standard Vote
Standard Vote (abbreviated as SV) is an election vote-counting method that chooses a single candidate by using ranked ballots and the sequential elimination of lowest counting candidates in two or three runoffs. Thereby addressing the unfairness of a single runoff voting system.
This method modifies instant runoff voting (IRV) by adding a second and possibly a third runoff with later-no-harm safeguards for runoff winners. It further modifies simple IRV by allowing the voter to mark more than one candidate at the same ranking level. These additions claim to improve on simple IRV by: more fairly counting a voter's honest opinion, making this system more monotonic (Monotonicity), reducing the failure rate for the Independence of Irrelevant Alternatives (IIA), eliminating Center-squeeze, and making the practice of Favorite Betrayal unnecessary.
Description[edit | edit source]
Voters rank the candidates using as many ranking levels as there are candidates, or to a limit as specified by the electing authority. Four levels is manually countable and a reasonable compromise as few voters will remember, nor be happy with, whomever their fifth and additional down ballot choices were.
This method begins with a first runoff. Candidates are eliminated one at a time in each runoff, with the vote counts of the final two candidates compared (effectively pairwise) to identify a winner and a runner-up. The method continues with a second runoff, in which the first runoff's runner-up is immediately withdrawn. The voter's preferences trapped behind/under the runner-up are now countable like those of other voters whose first preference has lost. This identifies a second runoff winner. If the first winner repeats as the second winner, they are elected and the election is over.
If no one is elected, a pairwise comparison is made of the first and second winners. The first winner will be elected if the second winner can do no better than a tie. Failing that, a third runoff occurs in which the first runoff's winner is immediately withdrawn. The votes previously trapped behind/under the first winner in both runoffs are now countable like those of other voters whose first preference has lost. This identifies a third winner. If the second winner repeats as the third winner, they are elected and the election is over.
If no one has been elected, a pairwise comparison is made of the second and third winners. The second winner will be elected if the third winner can do no better than a tie. Failing all of the above, the third winner is compared pairwise with the first winner. The third winner will be elected if they beat the first winner. Finally, with no one elected, the result is a paradoxical tie between the three runoff winners. One of them will be elected by "random draw".
Tie breakers[edit | edit source]
Random Voter Hierarchy (RVH) is used for each "random draw". Ideally these values are determined at the "instant" the counting begins, giving candidates and voters nothing to apply a strategy to. If two or more candidates have the same rank on any number of ballots, this tie is re-ranked by "random draw" en masse. All votes will fall the same way throughout all elimination rounds in all runoffs (all occurrences of A=B will either all count as A>B or all count as B>A). All ties encountered during elimination rounds will be decided by a different "random draw". This will cause ties between candidates to be decided in the same candidate's favor throughout all elimination rounds. In pairwise ties between runoff winners, the earlier winner's count takes precedence over a subsequent winner's count. In the scenario of the paradoxical tie, the candidate to be elected will be decided by yet another different "random draw".
Examples[edit | edit source]
The paradoxical tie. Each candidate has an equal claim to be elected. In this example, one of the three candidates will be elected by "random draw".
4 A>B
3 B>C
2 C>A
The next example shows how Standard Vote does not suffer from center-squeeze. Candidate C is elected.
4 A>C
3 B>C
2 C
The following example demonstrates that favorite betrayal is not necessary. C wins. 2 A>C turning into 2 C>A is not needed.
4 A>C
3 B>C
2 C>B
The 4th example illustrates the system doing a lot better than IRV at not failing to be monotonic
8 A
5 B>A
4 C>B
IRV elects B, but when 2 supporters of A change their votes to C (favorite betrayal), A wins. In this improved version of IRV, the original result still elects B, and the new result is a three way tie that will be decided by random draw. Still not monotonic but not the guaranteed win by A. However, the same result is achieved without betrayal, and not failing monotonicity, if those 2 voters had simply added C as a preference, casting A>C.