[EM] STV and weighted positional methods

Raph Frank raphfrk at gmail.com
Sun Feb 1 10:50:05 PST 2009


On Sun, Feb 1, 2009 at 6:04 PM, Kathy Dopp <kathy.dopp at gmail.com> wrote:
> OK, to get references to how it is a problem of exponential difficulty
> to count an STV election I am told to
>
> Google "Bartholdi STV" and you'll come up with many citations.

I think the point here is that it is very hard to manipulate PR-STV.
To work out the optimal strategic vote is NP-hard.

"(Bartholdi and Orlin, 1991) Manipulation of STV for electing a single
winner is NP-complete."

This doesn't mean that the election is NP complete to actually count.

It means that people are less likely to be strategic (as it is almost
impossible to actually work out the strategically optimal vote).



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