[EM] Quick and Clean Burial Resistant Smith, compromise

[Daniel Carrera]

On Sun, Jan 9, 2022 at 4:41 PM Kristofer Munsterhjelm <km_elmet at t-online.de>
wrote:

> > I couldn't figure out how to decide which voters need to be in the
> > coalition or what ballot they need to cast to maximize their chances.
>
> In quadelect (my election simulator), I just do this:
>
> for n = 1...numiters:
>         e_A = sample a random v-voter c-candidate election according to
> some
> given distribution
>         w_A = winner of e_A according to method M
>         for c_k in every candidate but w_A:
>                 for i = 1...strategy_iters:
>                         e_B = e_A
>                         for every ballot B in e_B:
>                                 if B ranks c_k ahead of w_A:
>                                         replace B with a random preference
> order
>                         w_B = winner of e_B according to method M
>                         if w_B = c_k:
>                                 then strategy successful
>         if strategy successful:
>                 increment number of strategy successes SS
>         else:
>                 increment number of strategy failures SF
>
> strategic susceptibility = SS/(SS+SF)
>
> It underestimates susceptibility with large numbers of voters but should
> give approximately the same results as JGA with his orders of magnitude.
>

Hmm... The numbers I'm getting are a lot smaller than those in the paper.
I'm using Benham, V=99, N=1, C=6 and the voters and candidates follow a
standard normal, just as in the paper. I chose those parameters because
Table 1 gives a strategic susceptibility of 0.622 which should be easy to
detect, but I'm only getting 0.00196; so off by over two orders of
magnitude. I don't have as many iterations (numiter = 100, strategy_iters =
100) but that should not change the overall scale.

It's hard to see how randomly shuffling ballots would be a strategy. I
tried changing the strategy: after the random ballot is generated,
candidate c_k is moved to the top and w_A to the bottom. That simple
strategy increases the susceptibility to 0.0785, but that's still one order
of magnitude off from the paper.

https://electowiki.org/wiki/Raynaud suggests that all versions of
> Raynaud pass ISDA, including Raynaud(GL). I agree, it would be useful to
> have a table, but it wouldn't be practical to render it for all criteria
> defined on electowiki; it would need some kind of interactive component
> so you could select just the criteria (and methods) that interest you.
>

I shouldn't get distracted with this right now, but maybe in a few months I
could make a Google spreadsheet --- a poor man's interactive database.

-- 
Dr. Daniel Carrera
Postdoctoral Research Associate
Iowa State University
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20220109/0a3f79ab/attachment-0001.html>