Instant runoff voting worked out fine in San Francisco

Well, I recall the thread, I posted with it to agree with you that multi-party systems, and I quote myself, “focus on the marketplace of ideas as the expression of freedom” and are what democracies should go for. I also say, “Ideas as such need a mechanism for competition, and that competition needs to be a forum for transparency.” I still think this is true, and I don’t want my post there to be taken otherwise… but transparency means a lot of things. You want votes to mean something, so that you can get a good idea of where people stand by checking the vote tally, but at the same time you want people to know what they’re getting out of someone winning, and that requires a sort of party-contraction so no one has unrealistic goals that they’re changing the world by helping to elect the one socialist member of the House or something.

It is not just politicians that should compromise, IMO. Voters should be able to express honest preferenes while also being realistic. You get better preferences out of multi-party systems, but you get distorted expectations when all these disparate politicans compromise two months later on a budget.

But one socialist member would make a real difference. For one thing, he or she would get at least some committee assignments and be in a position to inject a socialist perspective into the debates that shape legislation before it comes out for a floor vote. For another, in a multi-party system, there almost certainly would be no majority party, ever, in any legislature. (There is a majority party in South Africa but that’s rather a special case.) That means no party could ever be in a position to get its own way on everything. No legislation could pass unless it were a compromise cobbled together by several very different political camps, enough to form a voting majority.

I didn’t say it wouldn’t make a difference, I said it might bias unrealistic expectations. :slight_smile:

This is not a correct description of Condorcet voting because it assumes that the voter’s preferences are transitive. If a majority of the populace prefers A to B, B to C, and C to A, the final result should reflect that.

That’s why you need the voter to fill in the actual matrix with the pairwise races.

EM.org seems to describe Condorcet voting as I have. Does it really make sense to let voters cast circular ballots? I mean, some contradictions in the final sum may be normal, but what can you possibly learn from a single ballot that’s marked A>B, B>C, C>A?

That some voters can’t pick a single winner.

Anyway, I think I was mistaken.

I can see some uses for letting voters cast their matrix directly, but I think those could be taken care of by letting them rank candidates equally instead. If a voter likes A, B, and C equally, but doesn’t like D or E, he can rank A/B/C each #1 and leave the others blank (which will translate into A>D, A>E, B>D, B>E, C>D, C>E).

If there are only 3 candidates and he likes them all equally, he doesn’t need to vote in that race at all - he should have a blank matrix, not a self-contradictory one.

Looks like I posted too soon. The first IRV election in SF didn’t go so smoothly after all – the elections office still hasn’t been able to certify the result: http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2004/11/05/EDGPN9LHK51.DTL Apparently this is because of a bug in the software. “Conspiracy theories abound, as does security precautions for the computer and boxes of paper ballots that were wisely mandated as backup – and may yet have to be counted the old-fashioned way.”

Thanks to the design of IRV, that recount will probably take a lot longer than it has to. You can’t just count the ballots locally and report the number of votes for each of N candidates (as you could with approval voting), or each of N^2 - N pairs (as you could with Condorcet voting); you have to report the number of ballots cast for each of N factorial possible ranks.

For example, the race for County of San Francisco Supervisor District 5 had 22 candidates. I’m not sure if IRV was used for that race, but assuming it was, it’s impossible to break down the counting at all. 22 factorial is insanely huge, so they’d do better to read each ballot one at a time over the phone.

No, that’s not necessary. If you have several precincts each tallying ballot papers for a single electrate, then the person tallying the totals needs to tell each precinct who the lowest candidate is, whose votes get redistributed, and ask eachj precinct to lok at those, and say who the next choice is on those ballot papers. Repeat this each time you eliminate a candidate and get new totals.

The other way to do it would be to bring the ballots in to one central place to be counted. It’s possible that would save time, but it’s not necessary.

Questions:

  1. So how would this same scenario play out in Condorcet vote counting?

  2. Also, I guess assuming half like D as 2nd choice is hard to know in approval voting since we don’t ask what they prefer, just what they can live with. In that case, isn’t D a good compromise since A, B and C were “not voted” by 8 people each and D only by 6?

I’ll have to do some research for 1., but D is outside the Smith set, so no, D is not a good candidate.

The Smith set is the smallest set of candidates such that every candidate in the Smith set could beat every candidate outside the Smith set in a pairwise election. Condorcet voting guarantees that the winner will come from the Smith set, and no other system does.

Still confused about the voter experience for IRV versus Condorcet. For a race with five candidates, what does the ballot look like?

For IRV, it shows all five and I can pick one and stop or pick my first choice, a second choice, and then stop, etc. all the way to ranking all five. (I could also pick none, of course.)

What is it for Condorcet?

Any SF-based dopers who can describe how the ballot worked for these races?

Any updates to the counting since 11/6? It would be disappointing to see IRV get a black-eye just out of the gate. (Althought it sounds like an IRV ballot with Condorcet counting is the better option.)

I may have spoken too soon. I think D is in the Smith set for this election.

Note that in that scenario under IRV, there is no winner.

The same. There ought to be a method for you to rank candidates equally, so if you have no preference for several first choices, you can rank them equally.

Okay. But from a UI design, it is simpler to have the vote select their first choice, then gray out that choice and ask "Select a Second Choice or Cast Ballot. and so on.

Does not allowing you to choose multiple first choices or second choices, etc. invalidate Condorcet, i.e is it a requirement or an option?

Here’s one analysis of two problems with Condorcet:

These were addressed in the articles I posted earlier, but I’ll quickly recap.

That’s not a flaw of the system. If you get a non-transitive preference in the election results, it’s because that’s how the electorate actually feels. Trying to shoehorn non-transitive preferences into a transitive model is just a bad idea.

That can only happen if no candidate has strong support. Is there a meaningful way to pick a single winner in that case?

No one is saying that Condorcet is perfect. It’s not–it doesn’t satisfy the favorite betrayal criterion, which is a nice-to-have–but it’s a hell of a lot better than IRV, which doesn’t even have all the nice properties that our current system has (i.e., monotonicity).

As far as I can tell, the Condorcet algorithm returns A, B, and C as the set of winners. There’s just not enough information to pick any one of them.

By plurality and IRV, there’s no winner, as no one will vote D first. You end up with a three-way tie.