[EM] Anyone got a good analysis on limitations of approval and range voting?

[Kristofer Munsterhjelm]

Raph Frank wrote:
> On Tue, Nov 10, 2009 at 8:11 PM, Jobst Heitzig <heitzig-j at web.de> wrote:
>> Hello Kristofer,
>>> Assume (for the sake of simplicity) that we can get ranked information
>>> from the voters. What difference would a SEC with Random Pair make, with
>>> respect to Random Ballot?
>> This sounds interesting, but what exactly do you mean by Random Pair?
>> Pick a randomly chosen pair of candidates and elect the pairwise winner
>> of them? I will think about this...
> 
> Presumably, it means that the voter submits 2 ballots, a ranking and a
> nomination for the 2nd round?

In the context of SEC, it would be:

Voter submits two ballots - one is ranked and the other is a Plurality 
ballot. Call the first the fallback ballot, and the second the consensus 
ballot.

If everybody (or some very high percentage, e.g. 99%) votes for the same 
consensus ballot, it wins. Otherwise, construct a Condorcet matrix based 
on the fallback ballots. Pick two candidates at random and the one that 
pairwise beats the other, wins.

To my knowledge, Random Pair is strategy-free. It might also be 
proportional, but I'm not sure about that (partly because I'm not sure 
how you'd define "proportional" for ranked ballots).

You seem to be suggesting a more Condorcet way of doing the consensus 
balloting. A possible option would be to look at how e.g. Debian handles 
supermajority issues. On the other hand, grafting Condorcet onto the 
consensus option would make the actual consensus more opaque, and one 
may in any case argue: "if you have a consensus, there's an agreement 
and so you don't need a complex method to determine what the consensus 
actually is".