[EM] election strategy paper, alternative Smith, web site relaunch

[Jameson Quinn]

> A quick summary:
>

Quick reaction:


> ... I find that Hare and runoff are least frequently vulnerable to
> strategic voting, ...



>

... leaving aside the possibility of pairwise ties, I find that the
> existence of a sincere Condorcet winner is a necessary and sufficient
> condition for the existence of a core equilibrium in 8 of these 9 methods...


These two facts seem somewhat contradictory, since in order for Hare to
elect the Condorcet winner, voters must frequently use strategy. Are you
saying that strategy is even more frequent in other methods?

Also, what's your voter model? All possible sets of voter preferences? Real
elections, of course, frequently have much lower entropy than such a model;
but any other model involves questionable assumptions.

I'll read the paper and give further comments when I can.

JQ

> but that in the Borda count, it is necessary but not sufficient. The
> sufficient condition is for the Condorcet winner to have supermajority beats
> against all candidates, with sizes of at least [(2C-2)/(3C-2)]*V, where C is
> the number of candidates, and V is the number of voters.
>
> In addition to the nine methods listed above, I tried some of my analyses
> with six other Condorcet methods: beatpath, ranked pairs, Smith/Hare,
> alternative Smith, and two versions of cardinal pairwise. Beatpath and
> ranked pairs generally seem to perform like minimax, and cardinal pairwise
> usually but not always performs somewhat better than these, but the really
> striking news in my opinion is how well the Hare-Condorcet hybrids perform.
>
> That is, given a preliminary analysis, they seem to be as resistant to
> strategic voting as Hare (and possibly slightly more resistant), and they
> are distinctly less vulnerable to strategic nomination (because they are
> Smith efficient, and therefore only vulnerable to strategic nomination when
> there is a majority rule cycle). So, for single-winner public elections,
> alternative Smith and Smith/Hare seem to have a lot to recommend them, i.e.
> the combination of Smith efficiency with strong resistance to both types of
> election strategy.
>
> I should define these methods here, for clarity. Smith/Hare eliminates all
> candidates not in the Smith set (minimal dominant set, i.e. the smallest set
> of candidates such that all members in the set pairwise beat all members
> outside the set), and then holds an IRV tally among remaining candidates.
> This method has been floating around this list for a while, yes? Does anyone
> know of an academic publication that mentions it? I seem to remember reading
> something that said that it had been named after a person at some point, but
> I no longer know where I read that.
>
> Alternative Smith is a closely related method, which Nic Tideman made up
> when he was writing Collective Decisions and Voting. It (1) eliminates all
> candidates not in the Smith set, then (2) eliminates the candidate with the
> fewest top-choice votes. Steps 1 and 2 alternate until only one candidate
> remains. (See page 232 of the book.) I focus on this rule rather than
> Smith/Hare in the paper, because I find it marginally more elegant, but the
> difference between the two is very minor.
>
> my best,
> James
>
> P.S. My web site is back, mostly. The Antioch address got unplugged because
> of the split between Antioch College and Antioch University, so I've set up
> a new version of the site at http://www.econ.ucsb.edu/~armytage/voting/
> I've taken down several of the peripheral articles, though if anyone wants
> to see them (unlikely, I assume), I still have them on my computer. Comments
> on my most recent proxy voting paper (which is on the site) are still quite
> welcome, by the way.
>
>
>
>
>
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