User:Psephomancy/2D election simulation examples: Difference between revisions
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There are 3000 voters (black dots), 3 candidates (colored dots), and voters vote honestly, supporting the candidates who are most similar to them ideologically (nearest distance). |
There are 3000 voters (black dots), 3 candidates (colored dots), and voters vote honestly, supporting the candidates who are most similar to them ideologically (nearest distance). |
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*C is a partisan candidate on the right |
*C (green) is a partisan candidate on the right |
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*A is another partisan candidate, this time on the left |
*A (blue) is another partisan candidate, this time on the left |
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*B is a moderate candidate, and the best representative of the average voter |
*B (orange) is a moderate candidate, and the best representative of the average voter |
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== FPTP == |
== FPTP == |
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}} |
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== IRV == |
== IRV ("RCV") / Exhaustive Ballot == |
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A wins under [[Instant-runoff voting|Instant-Runoff Voting]] ("Ranked-Choice Voting"), after B is eliminated for not having enough first-preference votes, leaving A and C. (A is slightly closer to the center, so more people in the center support A over C.) |
A wins under [[Instant-runoff voting|Instant-Runoff Voting]] ("Ranked-Choice Voting"), after B is eliminated for not having enough first-preference votes, leaving A and C. (A is slightly closer to the center, so more people in the center support A over C.) |
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[[W:Exhaustive ballot|Exhaustive ballot]] behaves the same way, since it uses the same elimination rule as IRV, only held using multiple single-mark ballot runoffs instead of using a ranked ballot. |
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== Top-two runoff / Open primary == |
== Top-two runoff / Open primary / Contingent Vote == |
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A wins under [[Runoff voting|top-two runoff]] or an [[W:Nonpartisan blanket primary|open primary]]. |
A wins under [[Runoff voting|top-two runoff]] or an [[W:Nonpartisan blanket primary|open primary]]. A and C have the most votes and proceed to the runoff. (None of the candidates gets over 50% in the first round.) A is slightly closer to the center, so more people in the center support A over C in the runoff. |
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First round is the same as plurality: |
First round is the same as plurality: |
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[[W:Contingent vote|Contingent vote]] behaves the same way, except the runoff election is held automatically based on ranked ballots. |
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== Score == |
== Score == |
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[[File:2D election example Scores for A, B, C.png|800x800px]] |
[[File:2D election example Scores for A, B, C.png|800x800px]] |
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B wins under [[Score Voting]] (with normalized ballots), as they are the highest-rated overall by the voters. |
B wins under [[Score Voting]] (with normalized ballots), as they are the highest-rated overall by the voters. (Dark-colored voters gave that candidate a maximum score, white-colored voters gave them a minimum score.) |
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Latest revision as of 18:07, 5 December 2019
This is an example simulation of an election on a 2-dimensional political spectrum (such as the Political Compass, Nolan chart, Pournelle chart, etc.; it doesn't matter what the actual axes are.)
There are 3000 voters (black dots), 3 candidates (colored dots), and voters vote honestly, supporting the candidates who are most similar to them ideologically (nearest distance).
- C (green) is a partisan candidate on the right
- A (blue) is another partisan candidate, this time on the left
- B (orange) is a moderate candidate, and the best representative of the average voter
FPTP
C wins under first-past-the-post voting, since A and B split the votes of the left wing of the electorate. (If A hadn't run, then B would have won. If B hadn't run, then A would have won. But since they both ran in the same election, C won instead.)
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IRV ("RCV") / Exhaustive Ballot
A wins under Instant-Runoff Voting ("Ranked-Choice Voting"), after B is eliminated for not having enough first-preference votes, leaving A and C. (A is slightly closer to the center, so more people in the center support A over C.)
First round is the same as plurality:
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Second round after B is eliminated:
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Top-two runoff / Open primary / Contingent Vote
A wins under top-two runoff or an open primary. A and C have the most votes and proceed to the runoff. (None of the candidates gets over 50% in the first round.) A is slightly closer to the center, so more people in the center support A over C in the runoff.
First round is the same as plurality:
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Second round after B is eliminated:
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Score
B wins under Score Voting (with normalized ballots), as they are the highest-rated overall by the voters. (Dark-colored voters gave that candidate a maximum score, white-colored voters gave them a minimum score.)
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Condorcet
B also wins under Condorcet methods, as B would beat both A and C in head-to-head elections.
A vs B:
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B vs C:
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STAR
B also wins under STAR Voting. The first round is the same as Score, so the top-two winners are A and B (since A is slightly closer to the center than C):
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B is then preferred over A by a 66% majority.
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