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Author Topic: Information for Voters: Condorcet Voting  (Read 2687 times)

Offline Gulliver

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Information for Voters: Condorcet Voting
« on: April 07, 2007, 11:14:54 PM »
The Constitution of Taijitu states that both the election of the Delegate and the Speaker is to be done by a Condorcet vote.

What is Condorcet Voting?

Condorcet voting is a method of voting which chooses as the winner the candidate who is, when compared to all other candidates one on one, is overall preferred by a majority. The method is as follows.

Rather than voting for a single candidate, voters rank their candidates in order of preference. Using this information, each candidate is then paired off with every other candidate in a series of one on one contests. In each one of these contests a candidate receives a vote for every ballot cast in which they are ranked higher than their opponent. The candidate who wins all of these one on one contests by a simple majority is the Condorcet winner and the winner of the election.

On rare occasions no single candidate wins every contest and there is no Condorcet winner. Instead there is a loop of preference. For example, Alice beats Bob, Bob beats Charles and Charles beats Alice. In such a situation the loop is broken by removing from consideration the weakest loss, that is the contest in which the winner won by the smallest margin of votes. Thus in our example if the weakest loss was Bob's loss to Alice that loss would be removed, and things would resolve themselves as Bob defeating Charles who defeats Alice. And as Bob is at the top of this chain of contests, Bob is now the winner.

For more information, you can look here and here.

How to Vote

Voting in a Condorcet election is simple. All one has to do is to rank the candidates in order of preference. So, for an example between Alice, Bob and Charles, if one liked Alice the best, Bob the least and Charles more than Bob but less than Alice, their ballot would look like this:

Quote from: Condorcet Ballot
1. Alice
2. Charles
3. Bob

It's as simple as that.

For more information, you can look here.

Matrices

The final results of a Condorcet vote can be counted with and displayed best using a matrix. Take the following real example:

Quote
PoDSolySD
PoD01713
Soly707
SD12170

PoDSolySD
PoD0101
Soly-100-10
SD-1100

This is left beats top, so the numbers in the first table represent the number of ballots in which the candidate at left is ranked higher than the candidate at top.

The second table represents the outcome of each one on one contest between the candidates. The number is the margin of votes between the two. Blue and positive means that the candidate at left won. Red and negative means the candidate at top one. The winner is the candidate who wins each pairwise contest, so the candidate for which all the numbers to the right of their name at the left are blue and all the numbers under their name at top are red is the winner, in this case PoD.

Some spaces are left blank because a candidate cannot run against themselves.

For more information, you can look here.
« Last Edit: February 02, 2008, 09:53:18 PM by Cornelius Snuffles »

Offline Eluvatar

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Re: Information for Voters: Condorcet Voting
« Reply #1 on: July 31, 2007, 01:44:08 AM »
Current status of the vote:

Tabulation:
PURSDSoly
PUR037
SD12012
Soly730

Differences:
PURSDSoly
PUR0-90
SD909
Soly0-90


Remember, in these charts, left beats top.
Posted on: July 27, 2007, 09:39:59 PM
Sums:
PURSDSoly
PUR038
SD15015
Soly930

Differences:
PURSDSoly
PUR0-12-1
SD12012
Soly1-120
                                 
(click to show/hide)