Is it not still true that one of the great virtues of MJ is that it avoids Arrow's paradox? ________________________________ From: Election-Methods <election-methods-bounces@lists.electorama.com> on behalf of election-methods-request@lists.electorama.com <election-methods-request@lists.electorama.com> Sent: Wednesday, May 31, 2017 7:03 PM To: election-methods@lists.electorama.com Subject: Election-Methods Digest, Vol 155, Issue 21 1. Corollary to Arrow's Theorem (Rob Lanphier) 2. Re: Corollary to Arrow's Theorem (Juho Laatu) ---------------------------------------------------------------------- Message: 1 Date: Wed, 31 May 2017 08:50:52 -0700 From: Rob Lanphier <robla@robla.net> To: election-methods@lists.electorama.com Subject: [EM] Corollary to Arrow's Theorem Message-ID: <CAK9hOYm7sdQsneGyZVhNueBdetJpP-oWWM0_jnQEJ2kck8kD9Q@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Hi all, It appears that Randall Monroe has discovered an important corollary to Arrow's Theorem. It takes some patience to sort through it, but you'll find it described in this paper: <https://xkcd.com/1844/> Something to think about. Rob------------------------------ End of Election-Methods Digest, Vol 155, Issue 21 *************************************************

1. Corollary to Arrow's Theorem (Rob Lanphier)
2. Re: Corollary to Arrow's Theorem (Juho Laatu)

Arrow's theorem only applies to ranked systems, while MJ is a rated system (as are Score/Range, SRV/STAR, Approval, etc.) Later in life, Arrow supported rated systems: https://electology.org/ podcasts/2012-10-06_kenneth_arrow Gibbard's theorem is supposed to apply to all conceivable voting systems, though. On Mon, Jun 5, 2017 at 5:48 PM, steve bosworth stevebosworth-at-hotmail.com |electorama electowiki/Example Allow| <9zz1sjkwvt@sneakemail.com> wrote: > Is it not still true that one of the great virtues of MJ is that it avoids > Arrow's paradox? > > > ------------------------------ > *From:* Election-Methods <election-methods-bounces@lists.electorama.com> > on behalf of election-methods-request@lists.electorama.com < > election-methods-request@lists.electorama.com> > *Sent:* Wednesday, May 31, 2017 7:03 PM > *To:* election-methods@lists.electorama.com > *Subject:* Election-Methods Digest, Vol 155, Issue 21 > > > 1. Corollary to Arrow's Theorem (Rob Lanphier) > 2. Re: Corollary to Arrow's Theorem (Juho Laatu) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 31 May 2017 08:50:52 -0700 > From: Rob Lanphier <robla@robla.net> > To: election-methods@lists.electorama.com > Subject: [EM] Corollary to Arrow's Theorem > Message-ID: > <CAK9hOYm7sdQsneGyZVhNueBdetJpP-oWWM0_jnQEJ2kck8kD9Q@mail.gm > ail.com> > Content-Type: text/plain; charset="utf-8" > > Hi all, > > It appears that Randall Monroe has discovered an important corollary to > Arrow's Theorem. It takes some patience to sort through it, but you'll > find it described in this paper: > <https://xkcd.com/1844/> > > > Something to think about. > > Rob------------------------------ > > End of Election-Methods Digest, Vol 155, Issue 21 > ************************************************* > > ---- > Election-Methods mailing list - see http://electorama.com/em for list info > >

On 06/06/2017 01:22 AM, fdpk69p6uq@snkmail.com wrote: > Arrow's theorem only applies to ranked systems, while MJ is a rated > system (as are Score/Range, SRV/STAR, Approval, etc.) Later in life, > Arrow supported rated systems: > https://electology.org/podcasts/2012-10-06_kenneth_arrow > <https://electology.org/podcasts/2012-10-06_kenneth_arrow> > > Gibbard's theorem is supposed to apply to all conceivable voting > systems, though. Just to be precise, to all conceivable _deterministic_ voting systems. Any random method of the type: - With probability x%, choose the Random Ballot winner, - With probability (100-x)%, choose the Random Pair winner is strategyproof. It's also not very good. To be even more precise, Random Winner is also strategyproof as far as strategy from the voters is concerned, because the ballots are never looked at. It has an obvious teaming strategy, however. And dictatorial systems are strategyproof, but lacking for other reasons.

I just note that one could try nomination strategies / teaming also in Random Pair (e.g. 100 republican candidates against 1 democrat). BR, Juho > On 06 Jun 2017, at 12:32, Kristofer Munsterhjelm <km_elmet@t-online.de> wrote: > > On 06/06/2017 01:22 AM, fdpk69p6uq@snkmail.com wrote: >> Arrow's theorem only applies to ranked systems, while MJ is a rated >> system (as are Score/Range, SRV/STAR, Approval, etc.) Later in life, >> Arrow supported rated systems: >> https://electology.org/podcasts/2012-10-06_kenneth_arrow >> <https://electology.org/podcasts/2012-10-06_kenneth_arrow> >> >> Gibbard's theorem is supposed to apply to all conceivable voting >> systems, though. > > Just to be precise, to all conceivable _deterministic_ voting systems. Any random method of the type: > > - With probability x%, choose the Random Ballot winner, > - With probability (100-x)%, choose the Random Pair winner > > is strategyproof. It's also not very good. > > To be even more precise, Random Winner is also strategyproof as far as strategy from the voters is concerned, because the ballots are never looked at. It has an obvious teaming strategy, however. And dictatorial systems are strategyproof, but lacking for other reasons. > ---- > Election-Methods mailing list - see http://electorama.com/em for list info