[EM] Ranking unacceptable candidates.

[Kevin Venzke]

Hi Juho,



----- Mail original -----
> De : Juho Laatu <juho4880 at yahoo.co.uk>
> À : election-methods electorama <election-methods at electorama.com>
> Cc : 
> Envoyé le : Vendredi 18 octobre 2013 0h28
> Objet : Re: [EM] Ranking unacceptable candidates.
> 
> I think ranked methods should encourage full ranking. And I don't like 
> active truncation in general. The key reason is that if people start truncating 
> the worst candiates, and easily also their strongest competitors, then we start 
> losing valuable information. People may also start to truncate those candidates 
> whose supporters they expect to truncate their favourite candidates. In the 
> worst case we end up in having a plurality style election instead of a ranked 
> election (when people close to bullet vote, or rank only the candidates of their 
> own opinion group).
> 
> All information should thus be collected, and we should avoid opposite sides 
> truncating each others. I guess it is quite common the elected candidate is 
> disliked by many voters of the other opinion groups. But we still want to be 
> able to elect one of the canddate in a rational way (= using preference 
> information collected from the voters).
> 

I feel the major problem is that method designers have nothing to offer 
voters to persuade them to admit that the worse/worst frontrunners are
better than anybody. It would be extremely rare to find that one actually
needs the "worst frontrunner" as a compromise choice. It's totally evident
that giving a preference to this candidate can only (and should only!) have
the effect of helping him (even if it mostly does nothing), which is the
opposite of what the voter showed up at the polls to do.


>
> Additional cutoffs/categories/approvals may help us in collecting full rankings 
> from the voters. Harmless ranking is one approach to eliminating the risks of 
> complete rankings. 
>

I can point out a concrete example with "Single Contest," under which there
is an explicit approval cutoff, and adding or rearranging preferences among
disapproved candidates can never cause the defeat of a candidate who was
approved. It also doesn't open up any opportunities for other voters to take
advantage of the possibility that I might specify those preferences. 
(Contrast with MMPO, which still calls for defensive truncation despite
LNHarm.) I do think that this level of guarantee would make me want to submit
a full ranking.


Kevin Venzke