[EM] Defeat Strength

[Kristofer Munsterhjelm]

On 9/9/22 23:54, James Gilmour wrote:
> Kristofer If the last statement in your message below is correct,
> about how IRV been sold, all I can say is that those responsible have
> been engaged in serious misselling.
> 
> My description, well amplified by you, of how IRV works and is
> intended to work, is exactly as you set out below.  That is because 
> IRV, and STV more generally, is a contingency voting system.  It
> always has been, and it always will be.
> 
> Yes, that means IRV and STV-PR fail Condorcet and are not monotonic.
> But STV does comply with LNHarm, a criterion that is important to
> real voters in real elections.

You need borh LNHarm and LNHelp to provide immunity to burial, no?

If you have only LNHarm, then it's possible that an X>W>A voter can turn 
the winner from W to X by instead voting X>A>W, thus helping X. And if 
you have only LNHelp, then it's possible that an X-first voter harms X 
by voting X>W>A but doesn't harm X by voting X>A>W.

If only one of the LNHs is needed, then Descending Acquiescing 
Coalitions or Descending Solid Coalitions will get you mutual majority 
and the LNH in question -- and monotonicity.

-km