Single Non-Transferable Vote (SNTV)

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Brian Langstraat

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Feb 28, 2017, 11:59:25 AM2/28/17
to The Center for Election Science
Single Non-Transferable Vote (SNTV) is defined as:
In any election, each voter casts one vote for one candidate in a multi-candidate race for multiple offices. Posts are filled by the candidates with the most votes. Thus, in a three-seat constituency, the three candidates receiving the largest numbers of votes would win office. https://en.wikipedia.org/wiki/Single_non-transferable_vote

A good description of SNTV can be found at: http://aceproject.org/ace-en/topics/es/esd/esd04/esd04a/esd04a01.

My proposition is:
SNTV is be the simplest change to multi-winner elections (currently N-votes where N is the number of winners) that would reduce the chances of winner-takes-all by the majority (At-Large Approval Voting).

I am trying to find contradictions to this proposition such as a simpler change.

This is related to discussions under the topics:
Fargo Task Force recommends at-Large Approval Voting (https://groups.google.com/forum/#!topic/electionscience/A4YMD3FxCj4)

Brian Langstraat

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Jun 23, 2017, 2:18:42 PM6/23/17
to The Center for Election Science
A possible improvement to Single Non-Transferable Vote (SNTV) could be adding a possible Runoff round, so that the effects of spoilers and overly popular candidates may be reduced.

Single Non-Transferable + Runoff Vote (SNTRV):
1. Each voter casts one vote for one candidate in a multi-candidate race for N offices. 
2. If the N candidates with the most votes have a sum vote total that is more than the Winning Threshold, then the offices are filled by the N candidates with the most votes.
[Winning Threshold = Floor of ([Total valid votes] * N / (N + 1) +1) = "Inverse Droop Quota"]
[Example: Total valid votes = 100, N = 4, Winning Threshold = Floor of (100 * 4 / (4 + 1) +1) = 81]
3. If the N candidates with the most votes have a sum vote total that is less than the Winning Threshold, then a Runoff election is held where each voter casts one vote for one candidate in a race between the N+1 candidates with the most votes.
4. The offices are filled by the N candidates with the most votes.

This is essentially the general voting system used in FPTP+Runoff for the single-winner case.
It is similar to Single Transferable Voting (STV), but with a potential additional election, a different winning threshold, and a simpler (FPTP) ballot.

Brian Langstraat

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Aug 3, 2017, 6:33:58 PM8/3/17
to The Center for Election Science
A possible variation of Single Non-Transferable Vote (SNTV) could include districts and a round similar to Asset Voting, so nearly Proportional Representation (PR) could be achieved.

A common variation (Plan "two") of SNTV that includes districts already exists, but it has poor PR.

Districted Single Candidate-Transferable Vote (DSCTV):
1. Each voter casts one vote for one candidate in a multi-candidate race for N offices within N equal-population districts.
2. Valid votes are counted and distributed to each candidate.
3. Any candidate that receives at least the winning threshold and the most votes for the district in which they reside is a winner, while all other candidates in their district are losers.
[Winning Threshold = (number of valid votes) / (N districts)]
4. Excess votes remaining for the winners (beyond the winning threshold) and non-winners/losers (votes received) are calculated.
5. Within a time limit, the candidate with the most excess votes must transfer all of their excess votes to a non-winner (but not a loser) or lose their excess votes.
6. Steps 3 through 5 are repeated until no excess votes remain to transfer.
7. In the remaining district(s) without a winner, the candidate with the most votes is the winner.

If candidates are required to delegate their excess votes prior to the election, then DSCTV is essentially Testamentary Transferrable Voting (TTV) with Multiple District Groups (MDG) and (with Open-List) similar to Geographic Open List/Delegated (GOLD).

On Tuesday, February 28, 2017 at 10:59:25 AM UTC-6, Brian Langstraat wrote:

Brian Langstraat

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Sep 21, 2017, 7:46:29 PM9/21/17
to The Center for Election Science
A possible improvement to Single Non-Transferable Vote (SNTV) could have candidates delegate votes to non-candidates, so that some of the effects of wasted votes for popular candidates may be reduced.

Single Non-Transferable Delegatable Vote (SNTRV):
1. Each voter casts one vote for one candidate in a multi-candidate race for N offices. 
2. Any candidate that has at least the Winning Threshold wins and delegates their unused votes to a non-candidate.
[Winning Threshold = Floor of ([Total valid votes] / (N + 1) +1) = "Droop Quota"]
2a. Any non-candidate that has at least the Winning Threshold wins and delegates their unused votes to the original candidate's next non-candidate.
4. The remaining office(s) are filled by the candidates or non-candidates with the most votes.
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