[EM] Voting Benchmark

[Marijn Stollenga]

Yes, actually my main motivation was the strange properties in Schulze 
that I didn't like.
Firstly, the propagation of votes through beaten path sounds 
interesting, but it is also pretty strange. By voting a dominance of A 
over B, you might end up voting for C if some large other group votes C 
over A a lot, even if you don't like C at all. This leads to some 
complex tactical voting.

Secondly, the votes only flow if A over B has more votes than B over A 
say. On first sight this sounds good but introduces a sensitivity in the 
method that can completely flip results with a small change of votes, 
also leading to possible loss of votes and tactical voting. Why can't 
votes simply flow both directions? In my implementation I tried it and 
it still led to dominant results in my experiments, but I guess it's 
needed for certain properties?

Any thoughts?

Marijn

On 30/09/15 14:40, Kevin Venzke wrote:
> Hi Marijn,
>
> I think you might start with the criteria that motivated Schulze, or 
> criteria that differentiate popular methods.
>
> For instance:
> Schulze: clone independence, monotonicity (mono-raise), Condorcet, 
> Schwartz
> IRV: clone independence, later-no-harm, later-no-help
> Approval: participation, favorite betrayal (FBC)
>
> Unfortunately it's not necessarily straightforward to demonstrate that 
> a new method satisfies or doesn't satisfy some criterion.
>
> Some of us have simulations to attempt to gauge the incentives to use 
> specific strategies (e.g. compromise, truncation, burial). But since 
> simulations are based on the programmer's assumptions, nothing is 
> standardized.
>
> My hunch (based on my own experiments from 10+ years ago) is that if 
> Schulze is your original inspiration or standard, and you make your 
> own rank method, you may make something that gives similar results to 
> Schulze, but most likely it won't satisfy all of Schulze's technical 
> criteria.
>
> Kevin
>
> ------------------------------------------------------------------------
> *De :* Marijn Stollenga <m.stollenga at gmail.com>
> *À :* "election-methods at lists.electorama.com" 
> <election-methods at lists.electorama.com>
> *Envoyé le :* Mercredi 30 septembre 2015 4h12
> *Objet :* [EM] Voting Benchmark
>
> Hello,
>
> I am implementing a new election method, after initially playing with
> Schulze voting. In the process I really want to compare my method to
> Schulze and other methods according to several types of quality. Is
> there a good benchmark currently, that I can start from?
>
> Marijn
>
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