[EM] Another reason for LIIA

[robert bristow-johnson]

All's I know is that Ranked Pairs appears to get LIIA and Schulze does not.  And the two methods appear to be equally good in all other respects (and better than everything else): https://en.wikipedia.org/wiki/Ranked_pairs#Comparison_table 

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r b-j . _ . _ . _ . _ rbj at audioimagination.com

"Imagination is more important than knowledge."

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> On 05/29/2026 5:48 PM EDT Kristofer Munsterhjelm via Election-Methods <election-methods at lists.electorama.com> wrote:
> 
>  
> The Guardian 100 Best Novels thread got me thinking about a possible 
> additional benefit of LIIA (which may seem arbitrary otherwise).
> 
> Suppose you have an election with 100 candidates. You want to analyze 
> some properties of the top five in more detail, which is hard to do with 
> the full 100. Then if the election method in use passes LIIA, you know 
> that you can just batch-eliminate the 95 losers and the method's 
> behavior among those top five will be the same.
> 
> Most likely, the Smith set won't be five large, so you can do that with 
> any ISDA method. But LIIA may be useful in saying that there's never 
> going to be a situation where this goes wrong: where truncating at the 
> five best produces a different outcome.
> 
> Granted, since Smith sets usually are small and you can get the same 
> benefit by using an elimination method, it's not a strong case for 
> wanting LIIA. But even though it's not a strong case for LIIA, it has 
> some justification. Elimination methods also often have monotonicity 
> problems or chaotic behavior that LIIA methods don't, which I suppose is 
> due to LIIA being a more demanding global criterion, so that designing 
> something to pass it makes it unlikely that you fail monotonicity just 
> because "the pieces don't fit together", so to speak.
> 
> -km
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