[EM] Winning-votes intuitive?

[Blake Cretney]

Sorry I haven't replied on this thread for a while.  I think that I got
some agreement on some factual points, but didn't really explain why
these points mattered.

I admit that you can come up with examples where, because of irrational
voting, winning-votes is advantageous in terms of electing a sincere
CW.  I also admit that voters will sometimes vote irrationally.  But I
think we agree that as voters understand the method better, any claimed
advantage of winning votes over margins, at least with regard to the
truncation-resistance issue, vanishes.  This is because, as I've
established, there's no strategic benefit to truncation over
order-reversal (or random ranking).  

Note that I'm only talking about knowledge of the method here, not
knowledge of how others will vote.  My point is that even if you don't
know how other people are going to vote, truncation gives you no new
strategic opportunities, and so to voters who understand the methods,
there's no difference in strategy.

But since voters often won't understand the method, one effect will be
that voters who give incomplete rankings will tend to be punished for
their ignorance, whether these incomplete rankings represent trying to
get away with something, or not.  You could try to educate them, but
that defeats the whole purpose, because the idea of winning votes is
that voters will either use truncation or give up strategy entirely in
exactly those situations where they should rationally rank randomly or
order-reverse.  The presence of the partial ranking option on the ballot
seems to be there only to trick people into compromising their interests
in the hopes that some of those who are fooled deserve it.  

I think we'd have to be pretty desperate before suggesting a method that
only works because people don't understand it.  And so the argument is
that things are that desperate, that Marginal methods are too affected
by strategy to be usable.  Now, many people would argue that any
Condorcet method will be unusable because of strategy.  I think that is
false, and that by many measures Condorcet criterion methods tend to be
the most strategy resistant of the non-random methods.  And groups often
use tournament style voting, with essentially the same problems, without
much incident.  But that's a whole other subject.  My point is that
those who would argue that Marginal methods are too subject to strategy
should really give up Condorcet methods altogether.

This is because every example of truncation-resistance is an example
where the truncators could have got their way if they understood the
method better.  Ignorance is admittedly widespread, but I don't see how
we can count on it in every body we recommend Condorcet to.  So, I think
it is inescapable that if we abandon Margins, we must abandon
winning-votes as well. The truncation-resistance arguments against
Margins are really arguments against winning-votes too.

---
Blake Cretney


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