User:Randomstaplers/Article 1

Everything's broken. I'll fix it later; more revisions to come!

Originally called Let's Simulate IRV!

I've got a feeling that those pushing IRV (also known as RCV, or the CGP Grey 'alternative vote') at any cost, 'cause we need voting reform now!' have never actually seen IRV simulated, outside of charts provided by Grey. And that ignorance is, I believe, irritating those on the sub who have.

Votesim

The simplest computer simulation (as far as I know) only requires grade school geometry to understand. It was invented by Ka-Ping Yee in 2005 (no relation to any voter advocacy group, as far as I can tell). Results here.

The easiest way to generate your own images is to use Warren Smith's IEVS, which contains Votesim. 92k download here. You'll need to use the command line. If you're compiling, you'll need to #define HUGE and the source code has broken RNG, but it is more up-to-date, contains score-runoff voting and strategic voting settings.

As for how it works, well, Mark Frohnmayer rewrote Votesim again, this time by adding animations. His video pretty clearly describes Votesim's operation.

More Unrealistic Simulation Examples!

All models break down in some way. (See: Google Maps.) This model assumes everyone is honest, so Borda looks a lot like score, even though it has issues, (See point 2) because it cannot differentiate the difference between ranked ballots and cardinal ballots. It is also biased towards Llull winners (which Condorcet rediscovered in the 1700s, who knew?)

Edit: 9_Point_Buck points out that polling shows the approval threshold is different compared to what Votesim uses. Another reason models are broken.

All of the following methods have standard deviations of 50 and contain 16 candidates. Top-2 and IRV have another image with a deviation of 100 and 5 candidates. Another reason this model breaks.

One voter. One voter 2. The ideal model for this sim. And if you use a Llull method, you'll get the same result, even when hashed.

FPTP.

Approval. It did pretty well with 5 candidates, but 16 is just too much :(

Range/Score

Top 2 FPTP and Top 2, 2 and IRV and IRV 2. So why is IRV controversial?

Opinions ahead!

   There are situations where IRV produces worse results than Top-2 And in the multi-candidate simulation, IRV doesn't produce significantly better results than Top-2. What's the point in advocating for IRV in a Top-2 state, when there are better voting systems?
   IRV is absolutist. You support candidate 1, and only 1, until their elimination. Then support for candidate 2, etc. If a compromise candidate is eliminated, well...

   Let's say [Red], [Yellow], and [Green] are running in a ranked election.

   [Red] does well, but doesn't reach a majority, and causes [Yellow] to lose...

   [Yellow] is evenly split. (sic, but you can't determine how the vote will go)

So Green wins instead. Even though polling shows you would probably prefer Yellow, as the optimum candidate for society.

   Laboriously transferring votes when a candidate is eliminated? No easy way to count in precincts? Less transparency is the last thing we need when people don't even trust the simple FPTP system.

   IRV has been repealed before. The fact some of us are still advocating for it is insanity. (Insert your own word here, I got tired...) Oh, and if the big parties catch on to IRV's flaws, they might use the voting method as an excuse to never reform voting again!

At the end of the day...

I hope we take a more cautious approach to voting reform and not just jump on the IRV bandwagon.

TL;DR for commenters:

If you're concerned about model accuracy complaints from others, just point out Google Maps as an inaccurate model. Doesn't mean it's not useful. And yes, there are more models out there, they just require higher level maths...

Yes, this is targeted towards reformers (and the laymen) who haven't really thought of what they're promoting.

IMO, IRV's biggest problem is opinion point 1, that it may be worse than Top 2. If there was no runoff, I'd be in favor of it (reluctantly). But I live on the West Coast, which has a Top 2 primary. I'd probably vote against it. Link, and additional discussion.

Edits: Added the approval disclaimer, Google Maps example, and the section above. And more corrections. I'm going to license this post CC0 public domain, so feel free to change things and not cite me. And the bitmaps too.