[EM] 3 or more choices-Condorcet

[Juho Laatu]

On 14.11.2012, at 15.21, Michael Ossipoff wrote:

> There's no "best winner". We've been over that. But, if you really
> want a best winner, then look at the significant social optimizations
> of Approval and Score.

There may be different elections with different needs. The society is free to decide what criterion to use for each need. If you want to elect a candidate that gets a high sum of ratings, why not use Score. If you want to elect the most approved candidate, use Approval. If you want to elect a candidate that is preferred over all others, use Condorcet. (Take also the nature of the society into account since the votes may not be sincre enough.)

> Maybe, then, people should reluctantly give up the
> elusive goal of electing the CW. That's my take. Just work on reducing
> strategy needs, eliminating the worst strategy needs.

I'm more optimistic. My guess is that in most societies voters are sincere enough.

> But, what if there are 20 or 30 candidates? Wouldn't you prefer a
> method that doesn't make you need to rank the unacceptables?

In methods with 20 or 30 candidates many of the candidates may be irrelevant either in the sense that they will certainly not win, or in the sense that the voter doesn't care which one of the remaining candiates wins. In those cases truncation is quite ok. No information lost. It would however be good if the voters would rank all but one of those unacceptables that are potential winners (if the voter has such preferences).

> if ranking unacceptables is distasteful to you (as it is to me)

You should think that you are telling that the worst candidate is even worse than the second worst. That's what Condorcet methods anyway typically do, i.e. focus on pairwise losses rather than wins. That could make ranking of the worst candidates a pleasant experience. :-)

Juho