[EM] Strategy-free criterion

[Chris Benham]

Kevin,

> If one thinks GMC was contrived just to support Schulze(WV), it's worth asking how
> Woodall also managed to invent it (as CDTT).
Too easy. Woodall's  CDTT was merely a set and not a normative 
criterion.  He never said that he thought that the winner should come 
from the CDTT set.

> If I could prove that method XYZ was the best at
> sincere Condorcet efficiency (or substitute SU if you prefer), you would categorize
> that as mainly a marketing benefit?

Talking about sincere Condorcet efficiency (and not SU)  among methods 
that meet voted Smith, yes.  The sincere (voted or not) CW's status 
could be based on some very weak, barely existing, pairwise preferences. 
If the identity of this CW has been "concealed" by voters choosing (or 
not bothering) to express them, then big deal.

> I have nothing against explicit cutoffs.

I'm glad to hear it.  Methods in that category that meet Double Defeat 
cut through a few Gordian knots, and render all (or nearly all) of the 
rankings-only "defensive strategy" criteria irrelevant.

More on this later.

Chris B.

On 24/06/2024 7:38 am, Kevin Venzke wrote:
> Hi Chris,
>
> Chris Benham <cbenhamau at yahoo.com.au> a écrit :
>>> What I call inherently of value would be things like sincere Condorcet efficiency or
>>> reduced strategic incentives.
>>   
>> I can understand voted Smith-set fundamentalism, and that is expensive enough. But if
>> there is a top cycle I don't share the mind-set "Probably there is a sincere CW
>> (concealed by strategic truncation or order-reversal) and our top priority should be to
>> infer or guess who that is and elect him/her."  There may well be no sincere CW or a
>> higher SU candidate. So quite nice, but mainly just a marketing benefit.
> I'm not sure how to read this. If I could prove that method XYZ was the best at
> sincere Condorcet efficiency (or substitute SU if you prefer), you would categorize
> that as mainly a marketing benefit? To me this is the entire thing that the method
> is supposed to be doing.
>
>> https://electowiki.org/wiki/Strategy-free_criterion
>>   
>> If a Condorcet candidate exists, and if a majority prefers this candidate to another
>> candidate, then the other candidate should not win if that majority votes sincerely and
>> no other voter falsifies any preferences.
>>   
>> I think that is very similar to the Generalised Majority Criterion,
> It's much more limited.
>
>> enough for me to
>> reject it on the same grounds. And even if I didn't have that criticism, I don't see
>> why it's something we should care much about. It looks like something contrived just to
>> serve as ammunition against Hare and Margins.
> It does have that role, but Hare/Margins already fail the other criteria. I have
> always viewed SFC as an explanation of what could be improved in Approval.
>
> I would not say someone needs to care about SFC specifically, but it addresses
> truncation incentive, so it isn't useless to satisfy it.
>
>> (And possibly the similar GMC was contrived just to help promote the Schulze method.)
> If one thinks GMC was contrived just to support Schulze(WV), it's worth asking how
> Woodall also managed to invent it (as CDTT).
>
>> I would think that if the method
>> is making some attempt to minimise the number of "wasted votes", then
>> many voters would want to be able to express their full sincere ranking
>> and also would at least not mind giving their sincere or semi-sincere
>> approval cutoff.
> I have nothing against explicit cutoffs.
>
> Kevin
> votingmethods.net