Talk:No-show paradox

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What's the difference between the Participation and Monoticity criteria? Can someone think of an example where all Condorcet methods fail Participation? Why is it named Participation?

It has been proven by Hervé Moulin ("Condorcet's Principle Implies the No Show Paradox", Journal of Economic Theory, vol. 45, no. 1 , pp. 53-64, 1988) that the participation criterion and the Condorcet criterion are incompatible. A summary of his proof is here. Markus Schulze 22:58, 27 January 2006 (UTC)[reply]

Actually, the link that works for me is here. I suspect the version of mailman changed and the ids changed; if it happens again, the URL gives the month and the post is titled "Condorcet and Participation", by Marcus Schulze. Homunq (talk) 20:35, 22 June 2009 (UTC)[reply]

Thanks! That's a delightfully complicated proof. Paladinwannabe2 20:15, 23 October 2007 (UTC)[reply]

Participation v Monotonicity

The difference between participation and monotonicity is that participation relates to the addition of new ballots. Monotonicity relates to changes to existing ballots.

Relatively confusing

I've been reading the various pages on voting theory, and I must admit, this particular page (Participation Criteria) seems confusing. Is there any chance that it can be made a little more accessible? Once I understand it better, I will try to offer more concrete suggestions.

Well, the basic idea is that all possible sincere votes that a voter could cast should get a result that is at least as good as the result he gets when he just stays home. KVenzke 15:07, 10 May 2007 (UTC)[reply]

Examples

REMOVED THESE EMPTY SECTIONS (to be restored when fleshed out) Tom Ruen (talk) 01:22, 28 June 2008 (UTC)[reply]

Approval voting

Borda count

Instant-runoff voting

Kemeny-Young method

Minimax Condorcet

Plurality voting system

Range voting

Ranked Pairs

Schulze method

Weak-Participation

It seems to me that there should be a weaker version of Participation that says that a newly-added ballot shouldn't cause the defeat of a candidate whom it votes over every one of the other candidates.

Making that candidate lose by showing up and voting is much worse than just causing some lower choice to lose to a still lower choice.

Instant-Runoff wouldn't fail that Weak-Participation. Majority-Judgment and Condorcet would still fail it. — Preceding unsigned comment added by 65.8.176.249 (talk) 16:12, 13 November 2012 (UTC)[reply]

That criterion appears to be original research and/or another name for the Mono-Add-Top criterion, so I am removing it. 85.165.58.214 (talk) 14:50, 17 February 2013 (UTC)[reply]

Request: Merge all Condorcet methods

Condorcet methods are always incompatible with participation, i.e. we only need one example/proof for all Condorcet methods. Closed Limelike Curves (talk) 07:24, 28 February 2024 (UTC)[reply]

source for all highest median methods fail insufficient

https://en.m.wikipedia.org/w/index.php?title=Participation_criterion&oldid=1209710961

The source given here for highest median methods seems very exclusive to the bucklin method Sirati97 (talk) 18:03, 18 March 2024 (UTC)[reply]

The Quota rules example is odd

The example given for quota rule breach of the participation criterion is bad; the reason for its occurence in the pre-2013 German electoral system was the usage of overhang seats under Mixed-Member Proportional and the fact that the list seats were first apportioned to parties on the federal level and afterwards apportioned to the state lists of the specific parties.

I can explain it further, but the fact that the Negatives Stimmgewicht is still a thing even after the reform which changed Hare Quota to Sainte-Laguë Divisor (among other things) should say enough. It is even mentioned on the German Wiki site. Furthermore, the referenced chapter from Pukelsheim does not even blame the quota, it merely observers this phenomenon and then goes to talk about ideal seat share.

Generally speaking, I don't see how a basic quota system under normal conditions could break the participation criterion, considering that the number of votes cast always rises faster than the quota, but I am not qualiffied enough on that front I suppose. JerenMapper (talk) 22:17, 22 August 2024 (UTC)[reply]

I could've sworn this particular example was caused by both (the overhang seats interacting weirdly Hamilton's method at the state level), but if you can find a better explanation please let me know! – Closed Limelike Curves (talk) 00:56, 18 September 2024 (UTC)[reply]