[EM] Generalized symmetric ballot completion (was Hybrid/generalized ranked/approval ballots)

[Juho Laatu]

On 29.5.2011, at 16.06, Peter Zbornik wrote:

> On the other hand I might rather prefer "My Political Opponent" to be elected than "Pol Pot".
> Thus a ballot on the form A>X>My Political Opponent>Pol Pot, might be a good idea to allow.

I like this kind of explicit cutoffs more than implicit ones (at the end of the ranked candidates) since implicit cutoff easily encourages truncation. If people like to truncate their strongest opponents we might end up having bullet votes only. That would mean that we would be back in plurality, and all useful information of the ranked votes would be gone.

The explicit cutoff works well in elections where it is possible not to elect anyone (maybe keep the old elected alternative, or maybe arrange a new election after a while). One could also have elections where there are many possible outcomes, e.g. a seat for 6 months or a seat for 2 years (A>2y>B>C>6m>D). In these cases it is possible to measure quite reliably which candidates fall into which categories (e.g. "approvable enough"). The detailed rules on how to interpret e.g. a pairwise defeat to a cutoff entity have to be agreed.

Using the cutoff to give "negative votes" to candidates below the cutoff line (in the sense that such "negative votes" would really decrease their chance of winning candidates above the cutoff line) may be problematic since people could start giving negative votes to their worst competitors as a default strategy.

There have been also various proposals allowing strength of preference to be expressed (e.g. A>B>>>C>D>>E).

Juho