[EM] Poll for favorite single winner voting system with OpaVote

[Juho Laatu]

On 15.10.2011, at 23.24, MIKE OSSIPOFF wrote:

> Another "Oops!". I've just realized that I posted my most recent message to the wrong
> thread. So now I'm posting it to the right thread:
> .
> Oops! I forgot that B voters ranked C. 
> .
> Yes, C wins, even though C has a very low Plurality score. 
> .
> But PC isn't intended to be Plurality. In fact, none of us want Plurality, 
> so why should we use it for the standard for evaluating propoed 
> replacemens for it? Plurality is not what we want.

In addition to plurality related problems that example addresses also some other problems. If we consider the C voters to be just noise (only 3 of them) and the A and B votes reflect the true opinion of the voters, then the votes are 49 A, 48 B > C. That looks like nearly a tie between A and B. In this situation the unanimous opinion of those who said something about B vs C is that B is better. It is strange that those 3 votes can turn the situation upside down. But the details are not that important. I just wanted to point out that also this method makes sometimes weird decisions.

> .
> We don't say, "Don't vote for candidate X, because he isn't enough like
> the incumbant"
> .
> After all, if agreement with Plurality us which results are better than others, then
> wouldn't that imply that we should keep Plurality instead of replacing it?
> .
> We propose methods that meet criteria that are important to us, methods
> that do important things that we prefer.

I agree with "things that we prefer" but not with "meet criteria that are important to us". The reason is that criteria tend to be black and white, and we know that we need to violate some good criteria anyway. That may well sum up to a method that violates numerous criteria that we like, but it might violate each one only a little bit. And the end result might be the best possible, although we violated most of the (good) criteria that were under consideration.

> For me, that means getting
> rid of Plurality's lesser-of-2-evils problem as well as possible. PC and
> MMPO do so excellently.

Yes, if we have plurality and we want to allow more than two parties/candidates to run, then it would be nice to get rid of the lesser-of-2-evils problem. I'm however often confused about what do people want to have in this situation.

In presidential elections my additional question is if it is ok to elect candidates that are a compromise between two major parties but that do not have a strong party and lots of first preferences behind them. If that is ok, then all classical Condorcet methods work fine (with sincere votes at least).

This problem is a bit more difficult if we start using Condorcet to elect representatives in single-member districts. Is it ok if the method is not proportional at all but could in principle give most of the seats to a centrist party with only few first preference supporters. If the answer is yes, then we are probably building a political system that wants to avoid proportional representation as well as the traditional two-party system and wants instead to focus on simply electing good individual representatives. This is not a common approach in building political systems.

Alternatives to this approach could be to try to implement proportional representation or to keep the idea that the strongest party should win in each single-member district, but now without the lesser-of-2-evils problem.

My point is just that if we want to replace plurality in some elections we should also state what kind of outcome we want. Replacing plurality with Condorcet (although Condorcet methods are good general purpose single-winner methods) may not make the system any better (maybe worse). I need targets before I can say if Condorcet is better than plurality in some particular situation.

Juho



>  
> Mike 
> 
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