[EM] SODA arguments

Jameson Quinn jameson.quinn at gmail.com
Fri Feb 17 17:53:58 PST 2012

2012/2/17 Kevin Venzke <stepjak at yahoo.fr>

> Hi Jameson,
> Just a few thoughts.
>    *De :* Jameson Quinn <jameson.quinn at gmail.com>
> *À :* EM <election-methods at lists.electorama.com>;
> electionsciencefoundation <electionscience at googlegroups.com>
> *Envoyé le :* Vendredi 17 février 2012 9h20
> *Objet :* [EM] SODA arguments
>  For those who feel that Bayesian Regret is the be-all-and-end-all
> measure of voting system quality, that SODA's BR for 100% strategic voters
> will beat all other systems, including Range/Approval.
> I guess you will have a hard time arguing this, especially if you have
> multiple audiences. For instance, whether Range/Approval
> are even all that great is controversial. But if you're an
> anti-majoritarian type or think it's unfair/unrealistic to propose that
> voters
> are strategic, I guess that SODA looks like a step down.

I'm not sure that's true. Clay and Warren are the most hard-core BR
advocates, and probably I should let them speak for themselves, but... I
think their attitude is not that "strategy is evil" or "Range voters will
be 100% honest", but rather, "Some fraction of voters will be honest under
range, and that's good, so why not use range and let them?" In that case,
the fact that range voting is strictly better (by BR, and for a pre-chosen
arbitrary strategic percentage) than [IRV, Condorcet, MJ, etc], is an
important foundation of their argument. Finding a system which, while it is
worse than range for 100% honest, is actually better than it in some cases
(100% strategy, and presumably 99%, who knows where it stops), is an
important qualitative difference in the situation.

> Didn't you post an example where SODA declined to elect a "weak CW" that
> you said was actually a good thing? If that's
> true, I guess some people won't agree with that.

Yes. The basic setup is two major candidates and a weak centrist. The
weaker of the two majors gets to decide which of the other two wins. So if
the "weak CW" is truly a CW, they will be preferred by the weaker major,
and thus win; but if they are more weak than CW, then the weaker major
would rather allow the stronger major to win than stake their reputation on
electing the weak CW.

So in the end, it's more a question of giving a last chance to realize that
someone isn't really the CW, rather than not electing someone who is the CW.

> It seems to me that there would be a lot more candidates under SODA. It's
> pretty hard to spoil the race and there is benefit to
> be had in receiving some votes. It seems parliamentary that way. How many
> supporters is too few to consider running?

Well, there is the 5% cutoff, below which your votes are automatically
assigned for you.

> (I have a simple rule for cutting down the number of candidates. I don't
> think I've ever mentioned it because I know how
> idealistic you all are. Just say that the first-preference winner
> auto-wins if he has more first preferences than second and third
> place combined. This can make it risky even to compete for third
> place. The idea is that voters should definitely then realize
> which candidates are the top three in their race, which could amount to a
> viability/visibility boost for #3. My rule assumes
> there's no equal-ranking, but I bet something could be devised for other
> ballots.)

That rule doesn't sound too bad to me. Most of the time, there'd be no risk
of it applying; but I think it would still be a gentle pressure in the
intended direction. Still, I think it should be considered separately from
SODA per se.


> Kevin
> ----
> Election-Methods mailing list - see http://electorama.com/em for list info
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20120217/f4de137f/attachment-0004.htm>

More information about the Election-Methods mailing list