[EM] A much simpler proportional Condocet Method - BTR-STV

[Antonio Oneala]

    Now, I'm going to make the rather bold claim now that this is probably the only truly proportional method that doesn't rely on comparing all possible outcomes of an election or rely on party-lists.  Why is this?  Isn't STV proportional?  Well, STV is sort of proportional.  The problem is that it's method of transferring under-votes is exactly the same as IRV, and therefore, it's sort of a merger in between proportional and majoritarian methods.  This is probably the reason why no STV country has really developed into a multi-party state. 

CPO-STV, Sequential STV, and PAV, and that PCV method I came up with are completely proportional, but take forever to count because you have to compare every outcome.  

Now, first I'm going to introduce to you the idea of the proportional Condorcet winner.  The are several of these in an election, and the majority Conorcet winner is always among them.  A proportional Condorcet winner is the Condorcet winner of the minority of the electorate.  For instance, in a four seat election the a Proportional Condorcet winner would be the Condorcet winner of 25% of the populace.  The problem with simple Condorcet election methods like STV-CLE is that they only try to find the majority Condorcet winner.  It sort of shares the same problem with normal STV - it uses a majoritarian methods in the process of sorting through undervotes.

Now, the mehtod I'm about to propose is a variation of BTR-IRV.  BTR-IRV is a Condorcet majoritarian method.  What it is is just like normal IRV, but instead of eliminating the person with the least votes, you make an imaginary election between the two least vote getters and use the rank ballots to eliminate the one who the least people liked less than the other.  The Condorcet winner will always win this election, and so therefore will always rise to the top and be elected in the end.

Now, this method that I'm proposing differs slightly.  It uses a normal STV method for transferring the surplus votes.  Then in the elimination of undervotes round, instead of eliminating the one with the least votes and then transferring their votes, you take a set of the least-vote getters equivalent to the amount of seats in the election, plus 1, and eliminate the one who is the least preferred on the ranked ballots by the the electorate, then transfer that person votes.  Therefore, a proportional Condorcet winner will never be eliminated, and they will always rise to the top.  

Although the other methods may give out slightly worse results than the other, it is to be admired simply for simplicity purposes.  It's also easier to introduce to the electorate, simply by saying that this ensures that the best candidates will never get eliminated.

		
---------------------------------
New Yahoo! Messenger with Voice. Call regular phones from your PC and save big.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20060520/3e17aa81/attachment-0002.htm>