[EM] Thoughts on Burial

[C.Benham]

Jameson Quinn wrote (23 July 2010):

>In Australia (IRV), the clear strategy is to vote in a plurality-like way.
>That is, between two near clones A and B who share a majority, supporters of
>A, the one with least support from C voters, should betray and vote BAC. In
>the absence of such a strategy from A voters, C voters should dishonestly
>vote CAB, under the assumption that BCA and ABC are more common than BAC and
>ACB. Both of these strategies are simple enough to describe, especially if
>there's a pseudo-one-dimensional issue space. The favorite-betrayal one, if
>correctly applied, increases social utility and would probably dominate and
>suppress the burial strategy (since it's an effective defense). But as we
>can see with plurality, it also decreases incentives for conciliation from
>candidate B towards the A voters, allowing party B to become more corrupt
>over time.
>
>  
>

Jameson,

What exactly do you mean by the phrase "share a majority"?

I assume that in your scenario there are only three candidates. Is that 
right?

IRV is invulnerable to Burial strategy, and meets Majority for Solid 
Coalitions.

If  the A and B supporters (a majority of the voters) all  vote both  A 
and B above C then C can't win.

But if they don't then it is the supporters of the member of the pair of 
near-clones with the least support from the other
one that has the incentive to "betray" their favourite by using the 
Compromise strategy.

49: C>B
21: A>B
03: A
27: B>A

Of  the A-B pair of  "near clones" it is A who has the "least support 
form the C voters", but it is the supporters of B with
the incentive to betray by Compromising.

Chris Benham