[EM] [CES #4445] Re: Looking at Condorcet

[Jameson Quinn]

2012/2/5 Kevin Venzke <stepjak at yahoo.fr>

>
>   ------------------------------
> *De :* Jameson Quinn <jameson.quinn at gmail.com>
> *À :* electionscience at googlegroups.com
> *Cc :* EM <election-methods at lists.electorama.com>
> *Envoyé le :* Vendredi 3 février 2012 22h06
> *Objet :* Re: [EM] [CES #4445] Re: Looking at Condorcet
>
>
>  Condorcet systems fundamentally try to maximize the wrong thing. They try
> to maximize the odds of electing the Condorcet winner, even though it's a
> proven mathematical fact that the Condorcet winner is not necessarily the
> option whom the electorate prefers.
>
>
> Trouble is that the ballots ARE the voters' statements as to which
> candidate IS the CW.  The above paragraph seems to be based on the ballots
> sometimes not truly representing the thoughts of the voters voting them.
>
>
> No, he's saying that when the CW and the true, honest utility winner
> differ, the latter is better. I agree, but it's not an argument worth
> making, because most people who don't already agree will think it's a
> stupid one.
>
>
> From my perspective the trouble with the top statement is that sincere
> Condorcet efficiency and utility performance seem to be correlated. I don't
> know any way
> to design a method to specifically perform better at utility, assuming
> strategic voters.
>
> Note that, if you try to take this issue back to Warren's sims,
> strategically-voted Condorcet methods within his framework have not just
> bad utility but bad sincere
> Condorcet efficiency as well. (I don't know the numbers but it's
> impossible to believe they are any good.) So I don't know where one could
> look to argue that
> maximizing sincere Condorcet efficiency vs. utility performance can be
> done.
>
> This is an important point. I agree that it's basically impossible to
separate "(sincere Condorcet) efficiency" from utility in an election with
significant strategic voting. But in that case, as Kevin points out,
Condorcet methods are NOT necessarily the best way to maximize the former.

(And more research is needed to find out what is, because I don't trust
Warren's 10-year-old BR numbers on this question at all; his strategy
assumptions for several methods I find badly unrealistic. His numbers
establish a lower bound, but the realistic numbers could be significantly
higher for certain methods. And I'm not just unproductively criticizing
from the sidelines here. I'm busy working on research that would improve
this; I suspect that Kevin is, too.)

Jameson
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