Instant-runoff voting question

[theweaselking]

So, I'm watching the Hugo results, and a question has occurred to me. I expect Kevin Standlee will be *just a little busy* today, but he'll probably find this post sometime Tuesday because I said "Hugo Award" and "Hugo Voting" and answer. In the mean time, anyone know what happens in IRV when there's someone who *everyone* likes second-best?

Imagine a degenerate situation. 5 nominees, A B C D and E. First place votes are split almost evenly between A-D, with E getting zero first-place votes. EVERY SINGLE PERSON picked E as their second choice, no third or subsequent choices.

Round 1, E is eliminated, with no votes transferring.
Round 2, D is eliminated, all votes transferring to E (and thus into the void?)
Round 3, C is eliminated, all votes transferring to E. Were E still in the race, it would be firmly in the lead with slightly less than 50% of votes, to A and B's ~25%ish.
Round 4, A and B are remaining, with A having more votes than B. A wins. If E hadn't been eliminated, B would be eliminated, putting E firmly into first place with ~75% of the vote.

Is that actually how it works?
I realise my example is particularly degenerate, but it seems correct. And also Just Wrong(tm).

(In the mean time: Charlie Stross' My Little Pony/Lovecraft fanfic won a Hugo! That's awesome.)

EDIT: Oh sure, let's just throw my Hugo comments here, too: this is the first year I can remember where I've really liked all the winners. Gravity won best picture (and deserved it. Yes, it IS science fiction, all of those orbital mechanics bits, and the premise, are impossible. But it was great), the Rains Of Castamere was my second choice for Best Doctor Who Episode Written By Stephen Moffat but it wasn't a bad choice. The Short Story Hugo could have gone to *anyone* and it would have been good, and John Chu's entry was great. Ann Leckie took the triple crown, Kameron Hurley took home *2.5* awards[1] and deserved it, and the Racist Sexist Homophobic Dipshit Slate found themselves all fighting hard to stay above No Award, not always succeeding. It's funny how being terrible writers, writing bad works, and getting them nominated entirely by faux-victim political posturing doesn't actually win awards.


[1]: Best Fan Writer, Best Related Work, and the winners of Best Fanzine credit her (and her Best Related Work winner) for getting them into the running for Best Fanzine. They won on their own merits, but they thanked her for making people aware of them, and that's awesome.

Comments

[tyoko.livejournal.com]

Eliminated nominations can't accrue votes in most preference based systems, so E would get eliminated in the first round, and thereafter no vote for it would count. Since in your example, all the second choices were for E, the vote would effectively continue as a straight poll vote using only the first choices, so whomever gets the most first choices wins.

[theweaselking.livejournal.com]

That's what I was thinking. And that's disappointing: It means the Voting Wombat is wrong, and you *can* throw your vote away in certain degenerate situations by voting for the person you want, not the person you think would be okay and could win.

[tyoko.livejournal.com]

That's why most political systems that use preference voting only have a couple of rounds of elimination, designed to remove clear no-hopers, before the votes are tallied. They also have more than two choices, to ensure that at least part of your preference will count.

[prk.livejournal.com]

That's not how the Hugo voting works.

The Hugo count uses Australian Preferential Voting, where the preferences continue to flow.

This article - http://www.sf-encyclopedia.com/entry/hugo suggests that Americans may know it as "Instant Runoff Voting" - is that a well known term that encompasses continuing preference allocation?

prk
(An Australian who, for obvious reasons, is familiar with Australian Preferential Voting).

[theweaselking.livejournal.com]

Uh-huh. And tell me again how, IN MY PROPOSED SCENARIO, it doesn't devolve to "the vote would effectively continue as a straight poll vote using only the first choices, so whomever gets the most first choices wins."

(Also, see up at the top, where I say "instant-runoff voting" and the bits in the middle where I point out that votes are transferring, they're just all transferring to someone who's already been eliminated?)

[thornae.livejournal.com]

I think what prk has missed is the important qualifier "... no third or subsequent choices", which means that this situation would not be possible in the Australian voting system.
There, you must number all preferences (or let your first preference do so for you), or your vote doesn't count.

So, in the .au system, E would be eliminated, then 3rd and subsequent preferences for D, C, etc voters would be used to figure out who won.


... I'm pretty sure that this situation is one of the reasons why the .au system requires every box to be numbered.

[theweaselking.livejournal.com]

True - in Australia, my proposed scenario would result in every single ballot being spoiled.

In the Hugos, the more correct solution would be for everyone to go:
1) My Preference
2) E
3) No Award

E still wouldn't win, but it would come second place (to No Award) as A takes the first ballot and loses the No Award runoff, then E takes the second-place runoff by capturing A's second-choice votes, then D's (and maybe C's) to get more than 50%.

[thornae.livejournal.com]

Yah. That is, of course, assuming that most Hugo voters would have considered this scenario...

For all it's strengths, the Australian system does have its weaknesses, and the " guy that is everyone's second choice gets eliminated" effect is one of them. However, as moof points out, there's no way to get it perfect.


Also, the .au system leads to oddities like a 14 vote difference between minor parties deciding a senate seat (http://theconversation.com/what-has-happened-in-the-wa-senate-count-19797), leading to an unprecedented Senate vote re-count (which revealed nearly 1400 ballots had gone missing, although it's generally accepted this was through incompetence rather than malice).

As an expat and a bit of a fan of statistics, Antony Green's blog (http://blogs.abc.net.au/antonygreen/2013/10/western-australia-senate-count-summary-of-the-distribution-of-preferences.html) is always fun reading during the elections.

[prk.livejournal.com]

Huh, yes, I did miss that bit.

It makes it an entirely ridiculous scenario though.

prk.

[theweaselking.livejournal.com]

It's a deliberately-ridiculous scenario chosen to demonstrate a flaw: that everyone's second-favourite can lose out despite being *everyone*'s second choice.

[prk.livejournal.com]

Ahhh, okay.

Are there any outcomes that can't be demonstrated by a particular deliberately-ridiculous scenario?

prk.

[theweaselking.livejournal.com]

Turns out: No, it's been mathematically proven. (https://en.wikipedia.org/wiki/Arrow%27s_impossibility_theorem)

But *this* was one that I was surprised to see as a failure mode of IRV.

[secretagentmoof]

Since it's going to be mentioned sooner or later: mumble Arrow's Paradox mumble

[martinl-00.livejournal.com]

Yep. You can ALWAYS[1] come up with a scenario where the results of any voting system are unfair[2]. You can at best reduce how often they occur.

[1] In the sense that it's mathematically proven, so good luck weaselling.

[2] Arrow's definition of "unfair" is pretty math-y, but makes a lot of sense AFAICT.

[jayblanc.livejournal.com]

John Chu was entirely convinced he had lost out in the days leading up to it, so I'm really glad he won because he's such a nice guy in person as well as a great writer!

[matgb]

Yeah, it's a known issue, and why parties tend to put up the minimum candidates or minimum +1 to ensure no loss of preferences, etc. Condorcet counting would give E the win in this case (I think, haven't done the maths but it should do), but Condorcet is a weird system that doesn't give "winners" as such, it gives "least disliked", which is fine for some things and not others.

In multi-member seats, there's a difference effect, because in that there's a quote to reach, and if a candidate gets over the quota a proportion of their 2nd preferences are redistributed, but the Hugos and similar single winner effects don't do that.

[prk.livejournal.com]

The Hugo Awards use Australian Preferential Voting, where preferences continue to flow.

If someone prefers A, B, C, then D, and when A is eliminated B has also already been eliminated in a previous round, then their preferences go to C.

So in your scenario above:

Round 1, E is eliminated, with no votes transferring.
Round 2, D is eliminated, all votes transfer to their first available non-eliminated preference. Eg if all D voters had E second, then half had A third and the other half had C third then half of the D votes go to A, the other half to C.
Round 3, C is eliminated, all votes for C (including those that came from D) now get reallocated to their highest non-eliminated preference.

Eventually there is an entry (even if it's No Award) that reaches 50% + 1 vote.

prk

[theweaselking.livejournal.com]

I'm going to assume you just didn't read the original post at all.

[lafinjack.livejournal.com]

It's a fair cop, aye.

[frith]

Say what? A fanfic, a My Little Pony fanfic won a Hugo? @_@

[theweaselking.livejournal.com]

Er... not exactly. (http://www.tor.com/stories/2013/09/equoid)

It's more a unicorn bukkake story. But calling it "My Little Pony/Lovecraft fanfic" is funny.

[frith]

Oh well. I skimmed through it... snails and tentacles and a man-in-black in an All Creatures Great and Small setting. Lovecraftian overwrought prose. I bailed. I prefer the horror and gore-soaked mayhem of the Fallout Equestria novel I'm reading. I gather that Fallout is a violent game.

[theweaselking.livejournal.com]

Fallout tends to be violent.

(Want a copy of Fallout: New Vegas for PC? Easily the best of the series, one of the best games ever made, and torrain keeps spare copies around to hand out because she feels everyone needs more Fallout.)

[frith]

Aw, that's sweet, but no thanks! Video games really don't hold my attention. Beautiful full immersion habitats are fun to explore for a while, but I'm really not keen on chose-your-own-adventure, first-person-shooter, or platformer/side-scroller games.

[torrain.livejournal.com]

Fallout is a game in which many things are trying to kill you, and you are certAinly free to kill them back. I have found doing so very therapeutic in specific circumstances, although I find talking through the game's 6400 lines of dialogue way more interesting.

Wanna copy?

[frith]

It's very sweet of you to offer, but not my cup of tea. 8^) I'm just happy that Fallout Equestria is set 200 years in the future and none of the star ponies of MLP:FIM are getting murdered, raped or covered in gore (so far it seems they've all been dead and gone for 200 years).

[torrain.livejournal.com]

Okay. (FTR, for a more balanced view than comments to date: it is an RPG, not an FPS, and one of only two video game series that can regularly make me cry, laugh, spend hours on icons, and wax lyrical over a glass of wine, as well as containing what is possibly the top piece of epistolary fiction I have ever seen.)

[frith]

There is a fan-made game version of Fallout Equestria in the works. A demo video is here, and there is a dedicated forum, here.

[torrain.livejournal.com]

Before I go checking that out: how much rape is going on?

[frith]

I don't know how the game will handle the violence described in the book, the YouTube video only covers the part where Little Pip is still in Stable 2 (a giant multi-generational bunker that has been sealed off from the surface for 200 years). All the violence occurs in the Wasteland above. While the splattering of gore is experienced first-person by Pip as ponies next to her get shredded by gunfire, she has not been present while ponies get eviscerated, tortured and raped as yet (I'm just past chapter 20). She just sees the evidence that such things have occurred -- dead bodies used as decoration, gore everywhere, live ponies of all ages with blood between their legs due to repeated violent rapes... That's as far as it goes. What makes me roll my eyes is the warning about chapter 20.5 that comes on a business card inserted in the print copy. There's a romantic lesbian sex scene in which Pip is very happy. There's a lot of licking and spasms involved.The business card gives detailed instruction as to where to stop reading and how far to skip ahead, this part of the book is "not suitable for younger readers". LOL. Riiiight. Rooms full of slaughtered ponies, bloated corpses in cages, piles of skeletons, and herds of fast zombies, this is OK, and lusty lesbians lovingly licking... isn't. 9_9

Time for work! I'm late!

[torrain.livejournal.com]

Mmmmyeah. I certainly grant that these things are not the kind of things that cannot exist in the Fallout-verse, and I am sure it is reasonable to infer this kind of thing exists in certain situations therein!

That said, I love Fallout a great deal for many reasons, not the least of which is its persistant, flawed, compromised idealism, and I think that'll lead me to pass on any version of it that's been grimdarked into loudly featuring the rape of children.

[lafinjack.livejournal.com]

Your link goes to the Hugo 'full details', and I'm not familiar enough with this year's batch, so talking about a 'Racist Sexist Homophobic Dipshit Slate' doesn't really narrow down the slate at all for me. We ARE talking about SF/F, after all.

Ancillary Justice and Equoid were great, as was We Have Always Fought, and Gravity was good. I've bought Hurley's essay compilation along with The Water That Falls On You From Nowhere and The Lady Astronaut of Mars. Haven't really paid attention to Time since the original mysterious solo comic came out, I guess I should probably try to figure out how to read it.

[theweaselking.livejournal.com]

There was an organised effort to nominate bad-to-middling works by terrible people for political reasons, for the standard fake victim "we're the moral ones, and a majority, and REAL Americansfans, but those dirty homo leftist commie misandrist peaceniks hate us and so we never win awards!" reasoning.

This is why you'll see nominations for Larry Correia, Brad Torgerson, and Ted "Vox Day" Beale. All of which lost big, with Beale losing to "No Award". Because the best of them (Correia) was a generic, unimaginative, and jingoistic mediocre novel, and the rest were worse than that, and they only made the ballot at all through a political stunt.

[lafinjack.livejournal.com]

Thanks for the update.