Re: Problems with the majority requirement
On Fri, May 30, 2003 at 09:02:27PM -0400, Raul Miller wrote:
> On Fri, May 30, 2003 at 03:22:21PM -0400, Andrew Pimlott wrote:
> > 1. A voter who sincerely prefers the default over some other option
> > is in effect pursuing a "meta-strategy"--ie, one that is outside the
> > voting system per se.
> I guess you mean that if the vote defaults the issue is not resolved by
> the vote.
My understanding is that a win by "further discussion" will
generally be followed shortly by another vote, and that when there's
a possibility to expressly do nothing, that will be a separate
option. So a voter for "further discussion" either honestly thinks
not enough debate has occurred, or think he can somehow do better in
a revote, perhaps by persuading people, or perhaps (and this is more
what I was getting at) by wearing down the other side--causing the
votes to end in a tie until he gets his way. Sort of like a
> > 2. A voter who sincerely prefers some option over the default may
> > still have an incentive to vote the default higher. By weakening
> > the demoted option, he may cause his favorite to win.
> Or he may cause the vote to default (where, as a general rule, most of
> the options aren't especially popular). Or, he may cause his favorite
> to lose (where, as a general rule, most of the options are popular but
> people have differing ideas of which is best).
> > This is true
> > in straight Condorcet systems, but is more likely in the proposed
> > system, given the "knockout punch" of the default option.
> Actually, it depends on what other people think. It's certainly not an
> "always succeeds" strategy.
Absolutely true. But if we haven't worked out all the odds, it
remains a possibility that some clever person will find a way to get
a statistical edge. Like counting cards--it doesn't win any
particular hand, but it gets you kicked out of the casino in the
Further, this possibility is more remote in straight Condorcet,
which has been analyzed by more people.
> > 3a. Due to the inherent meaning of the default option, voters will
> > typically not consider it especially undesirable (unless they
> > strongly feel that a revote will create tension or damage Debian's
> > reputation...).
> This is only true for voters who think that the vote will not accomplish
> anything worthwhile.
They might think the vote is very worthwhile--but that there is
little harm in delaying the outcome a few weeks for a revote or two.
> > This inclines voters to insincerely promote the
> > default option, since causing the default to win is a small penalty.
> > Arguably, a voting system should counterbalance this inclination.
> Here, you seem to be saying that the voting system should force people to
> choose between the lesser of two evils, even when they're opposed to both.
No, no--just that it shouldn't make the default option too tempting.
> >  As an aside, there is a case that vexes me considerably, and it
> > pertains to pure Condorcet/CpSSD. Say you have sincere preferences
> > 8 ABC A>B 8:7 A wins
> > 7 BAC A>C 15:5
> > 5 C B>C 15:5
> > If only A swaps B and C, the outcome is the same. If only B swaps A
> > and C, B wins in the tie-break (A>B 8:7, C>A 12:8, B>C 15:5). If
> > both swap, C wins outright.
> I don't have a clue what you're saying, here. A is an option, how can
> an option swap two other options?
Sorry, this was a thought that I just dashed off, and you can ignore
it. But if you want to understand what I meant: I was using "A" as
both the option A, and the contingent (pretend for the moment that
they are a bloc that acts in concert) that favors A (then B then C).
My vexation is that I've convinced myself that if everyone is
rational and willing to vote strategically, then "second-place"
candidate will win, because its backers can improve their outcome by
ranking the lower preferences insincerely, whereas A's backers
cannot. This is highly counter-intuitive to me. But again, this
has nothing to do with the proposal, only with Condorcet plus any of
the tie-break mechanisms I've seen.