[EM] Results for Poll for Favorite Single-Winner Voting System
Jeffrey O'Neill
jeff.oneill at openstv.org
Tue Oct 25 14:51:31 PDT 2011
The results are in for the Poll for Favorite Single-Winner Voting System.
Note that I deliberately used the word "Favorite" and not the word "Best".
The results indicate merely the preferences of the voters (a small and
biased sample) and should not be take too seriously. I find the results
interesting because they provide clues as to what people who like one voting
system think of other voting systems. If the results below are not formatted
correctly, this is also posted on my blog at http://www.openstv.org/node/165
Regardless of which way you count the votes, Instant Runoff Voting is the
winner. Results are shown below for (1) Instant Runoff Voting, (2) Condorcet
Voting, (3) Approval Voting, (4) Borda Count, and (5) Coombs Method. I find
these all to provide interesting information. Ballots are available here:
http://www.opavote.org/vote?ekey=agNzdHZyEAsSCEVsZWN0aW9uGO25GQw
Instant Runoff Voting
IRV had double the votes of the next runner up in the first round and
maintained a clear lead through the end with a final tally of IRV 18 and
Condorcet 11 with 3 exhausted votes. Some highlights:
- The 2 Range Voting votes went to Condorcet and Approval. Not much of a
surprise.
- Of the 4 Approval votes, only 1 went to Condorcet with the other 3
being exhausted. I expected all of these to go to Condorcet.
- Of the 5 Other, 3 went to IRV. I would have expected the Other votes be
people who wanted something rather complex and would not be IRV supporters.
Condorcet Voting
This one mostly speaks for itself. I was surprised that Borda only beat
Plurality by 12 to 7 and that there were a few people who voted Plurality
higher than Approval, Range, Coombs, and Bucklin. Perhaps some voters did
not know the details of these other voting systems. This illustrates a
totally different problem with elections: unknowledgeable voters who don't
take the time to learn about the candidates.
Approval Voting
This one has to be taken with a grain of salt. I counted a vote as an
approval if the candidate was ranked. Since 14 voters ranked all the
candidates and likely didn't actually approve of them all, I am
overcounting. Nonetheless, there are some interesting nuggets.
IRV, Condorcet, and Approval were all very close in the number of approvals.
I'm surprised that Coombs is among the least approved as I think it is a
good one (it was my first choice).
Borda Count
In doing the Borda Count, I "completed" the ballots, meaning that all
unranked candidates on a ballot shared the remaining count for the ballot.
The eliminates some of the impact of strategic voting with the Borda Count.
Again, IRV, Condorcet, and Approval were all significantly ahead of the
others. I find it interesting that Condorcet is much closer to IRV with this
method. This is probably due to the fact that many Condorcet supporters
strongly dislike IRV, while the converse is less likely to be true (in my
opinion).
Coombs Method
Lastly, Coombs method. As I noted above, this was my first choice. With the
Coombs method, the candidate with the most last place votes is eliminated at
each round. Since centrist candidates are less likely to be eliminated,
Coombs is more likely than IRV to elect the Condorcet winner.
The least liked candidates in order are: (1) Plurality, (2) Other, (3)
Borda, (4) Coombs, (5) Bucklin, (6) Range, (7) Approval, (8) Condorcet, and
(9) IRV.
Summary I hope you found this to be an interesting exercise. I will do it
again for multi-winner voting systems next month. Please contact me directly
to make nominations.
------------------------------
Counting votes using Instant Runoff Voting.
R|Instan|Plural|Condor|Borda |Approv|Range |Coombs|Buckli|Other |Exhaus
|t runo|ity vo|cet vo|count |al vot|voting| metho|n syst| |ted
|ff vot|ting |ting | |ing | |d |em | |
|ing | | | | | | | | |
========================================================================
1| 14| 0| 7| 0| 3| 2| 1| 0| 5| 0
|---------------------------------------------------------------------
| Count of first choices.
========================================================================
2| 14| | 7| | 3| 2| 1| | 5| 0
|---------------------------------------------------------------------
| Count after eliminating Plurality voting, Borda count, and Bucklin
| system and transferring votes. Since this is the first elimination
| round, all candidates without any votes are eliminated.
========================================================================
3| 15| | 7| | 3| 2| | | 5| 0
|---------------------------------------------------------------------
| Count after eliminating Coombs method and transferring votes.
========================================================================
4| 15| | 8| | 4| | | | 5| 0
|---------------------------------------------------------------------
| Count after eliminating Range voting and transferring votes.
========================================================================
5| 15| | 9| | | | | | 5| 3
|---------------------------------------------------------------------
| Count after eliminating Approval voting and transferring votes.
========================================================================
6| 18| | 11| | | | | | | 3
|---------------------------------------------------------------------
| Count after eliminating Other and transferring votes. Candidate
| Instant runoff voting is elected.
Winner is Instant runoff voting.
------------------------------
Counting votes using Condorcet Voting.
Pairwise Comparison Matrix:
|Inst|Plur|Cond|Bord|Appr|Rang|Coom|Buck|Othe
----+----+----+----+----+----+----+----+----+----
Inst| 0| 28| 18| 26| 24| 23| 25| 24| 22
Plur| 0| 0| 0| 7| 2| 5| 4| 3| 4
Cond| 11| 26| 0| 24| 23| 22| 22| 22| 22
Bord| 2| 12| 3| 0| 8| 7| 8| 8| 9
Appr| 8| 24| 8| 18| 0| 18| 18| 17| 11
Rang| 6| 16| 4| 14| 9| 0| 12| 12| 9
Coom| 3| 12| 4| 10| 8| 8| 0| 7| 9
Buck| 5| 13| 4| 10| 8| 7| 9| 0| 6
Othe| 6| 16| 6| 11| 15| 14| 11| 13| 0
Smith Set: Instant runoff voting
------------------------------
Counting votes using Approval Voting.
Candidate | Count
=============================
Instant runoff voting | 28
Plurality voting | 14
Condorcet voting | 26
Borda count | 17
Approval voting | 25
Range voting | 19
Coombs method | 14
Bucklin system | 14
Other | 17
Exhausted | 0
Winner is Instant runoff voting.
------------------------------
Counting votes using Borda Count.
Candidate | Count
=============================
Instant runoff voting | 202.5
Plurality voting | 67.0
Condorcet voting | 190.5
Borda count | 96.5
Approval voting | 140.5
Range voting | 117.0
Coombs method | 104.0
Bucklin system | 106.0
Other | 128.0
Exhausted | 0
Winner is Instant runoff voting.
------------------------------
Counting votes using Coombs Method.
R|Instan|Plural|Condor|Borda |Approv|Range |Coombs|Buckli|Other |Exhaus
|t runo|ity vo|cet vo|count |al vot|voting| metho|n syst| |ted
|ff vot|ting |ting | |ing | |d |em | |
|ing | | | | | | | | |
========================================================================
1| 14| 0| 7| 0| 3| 2| 1| 0| 5| 0
|---------------------------------------------------------------------
| Count of first choices.
========================================================================
2| 14| | 7| 0| 3| 2| 1| 0| 5| 0
|---------------------------------------------------------------------
| Count after eliminating Plurality voting and transferring votes.
| Last place votes: Instant runoff voting, 0.575000; Plurality voting,
| 9.109524; Condorcet voting, 0.866667; Borda count, 3.476190;
| Approval voting, 1.134524; Range voting, 5.109524; Coombs method,
| 4.976190; Bucklin system, 3.309524; and Other, 3.442857.
========================================================================
3| 16| | 7| 1| 4| 2| 1| 1| | 0
|---------------------------------------------------------------------
| Count after eliminating Other and transferring votes. Last place
| votes: Instant runoff voting, 1.678571; Condorcet voting, 1.021429;
| Borda count, 3.888095; Approval voting, 3.309524; Range voting,
| 5.438095; Coombs method, 5.638095; Bucklin system, 5.088095; and
| Other, 5.938095.
========================================================================
4| 17| | 7| | 4| 2| 1| 1| | 0
|---------------------------------------------------------------------
| Count after eliminating Borda count and transferring votes. Last
| place votes: Instant runoff voting, 1.833333; Condorcet voting,
| 1.116667; Borda count, 7.433333; Approval voting, 3.566667; Range
| voting, 5.766667; Coombs method, 6.183333; and Bucklin system,
| 6.100000.
========================================================================
5| 18| | 7| | 4| 2| | 1| | 0
|---------------------------------------------------------------------
| Count after eliminating Coombs method and transferring votes. Last
| place votes: Instant runoff voting, 2.100000; Condorcet voting,
| 1.300000; Approval voting, 4.950000; Range voting, 7.383333; Coombs
| method, 8.216667; and Bucklin system, 8.050000.
========================================================================
6| 18| | 7| | 5| 2| | | | 0
|---------------------------------------------------------------------
| Count after eliminating Bucklin system and transferring votes. Last
| place votes: Instant runoff voting, 4.750000; Condorcet voting,
| 1.666667; Approval voting, 5.583333; Range voting, 8.500000; and
| Bucklin system, 11.500000.
========================================================================
7| 18| | 8| | 6| | | | | 0
|---------------------------------------------------------------------
| Count after eliminating Range voting and transferring votes. Last
| place votes: Instant runoff voting, 6.000000; Condorcet voting,
| 2.333333; Approval voting, 9.333333; and Range voting, 14.333333.
========================================================================
8| 18| | 11| | | | | | | 3
|---------------------------------------------------------------------
| Count after eliminating Approval voting and transferring votes. Last
| place votes: Instant runoff voting, 6.500000; Condorcet voting,
| 4.000000; and Approval voting, 21.500000.
========================================================================
9| 28| | | | | | | | | 4
|---------------------------------------------------------------------
| Count after eliminating Condorcet voting and transferring votes.
| Last place votes: Instant runoff voting, 12.500000; and Condorcet
| voting, 19.500000. Candidate Instant runoff voting is elected.
Winner is Instant runoff voting.
_________________________________________________________
OpenSTV -- Software for counting STV and ranked-choice voting
OpaVote -- Online elections for ranked-choice voting
http://www.OpenSTV.org
http://www.OpaVote.org
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