[EM] Condorcet strategy and anti-strategy measures

[Dave Ketchum]

A BIG straw, hung out on a VERY WEAK stem:

If this argument managed to kill Condorcet, IRV is the strong contender - 
which is subject to much stronger complaints,

Conceded that a private group might contain the ability and willingness 
for strategies of this sort, public elections have to be about immune.

Potential strategists have to predict the expectable results with no 
effort and what effort will promote a better result without going into 
something worse.

Here Bush backers are accused of promoting ranking Nader ahead of Kerry 
for strategy reasons:
      If Kerry backers join in, they may manage to elect Nader.
      Could be Bush would have won, if strategy people got fired.
      MANY (hard to count) Bush and Kerry backers will rank Nader second 
for valid, rather than strategy, reasons.

Back to EDUCATION - such results are best accepted, unless REAL scams are 
visible.

BTW - adding reruns to Condorcet looks mostly like a way to make it look 
uglier and more expensive.

Dave Ketchum

On Wed, 26 May 2004 03:51:13 -0400 James Green-Armytage wrote:

> Dear Mike, and all election methods fans,
> 
> Mike wrote:
> 
>>First, I don't believe that Condorcet wv has a serious strategy problem. 
>>We've often discussed the defensive truncation strategy. Here's how I
>>often 
>>word it: The only way you can steal the election from other voters is if 
>>they were trying to help you. Doesn't that make you proud of yourself?
>>
> 
> 	I do believe that Condorcet wv had a serious strategy problem.
> 	While it is unknown how likely a successful execution of the burial
> strategy would be in a public election, I believe that if it did occur, it
> would produce an *extremely* negative reaction towards both the result and
> the election method itself. 
> 	Imagine if Kerry beat Bush by a few hundred thousand votes, and yet Bush
> actually won the election because most of the Bush voters strategically
> ranked Nader second, creating a fake Nader > Kerry victory to knock Kerry
> out of the running.
> 
> 	Something like this, for example.
> 44%: Bush > Nader > Kerry
> 5%: Bush > Kerry > Nader
> 38%: Kerry > Nader > Bush
> 5%: Kerry > Bush > Nader
> 8%: Nader > Kerry > Bush
> Bush : Kerry = 49 : 51
> Bush : Nader = 54 : 46
> Kerry : Nader = 48 : 52
> 
> 	If this was a single-balloting wv Condorcet election, and Bush won (as
> above), there would be an enormous outrage, and it would be entirely
> justified.
> 	In that sort of situation, you would really want to hold a second
> balloting. In between ballotings Nader would be given the opportunity to
> drop out of the race, and hopefully he would do it (based on the idea that
> significant number of the Bush > Nader > Kerry votes are strategic). Then
> you would have a straight contest between Bush and Kerry, which Kerry
> should win.
> 	Is an example just like this very likely? No, I guess it's probably
> pretty unlikely. (However, I think that there are other kinds of examples
> where successful burying strategies are a bit easier and more plausible...
> I think that I've provided some of these examples already...) But anyway
> it is *possible*, and the possibility of such a disaster justifies at
> least one more balloting.
> 	And yes, Mike, I *do* think that just one more balloting in the event of
> a majority rule cycle would be a great help. 
> 	Let me put it this way: Without a second balloting, I would not
> necessarily feel comfortable about recommending Condorcet for public
> elections instead of something like IRV. 
> 	Not because IRV is a good election method (it isn't, really), or because
> the Condorcet principle is unimportant (I think that it's extremely
> important), but because a successful burial strategy or an out-of-control
> chicken game in single-balloting Condorcet would just undermine the
> democratic process too severely, and I wouldn't feel comfortable in
> opening up the possibility for that. 
> 	With a second balloting, I would say that Condorcet is vastly superior to
> IRV and pretty much any other public election method around.
> 
> 	Mike, in your analysis of Condorcet strategy, you seem to be assuming
> more coordination, more communication, and more time for people to respond
> to each other's strategies than what I think is necessarily realistic. In
> a previous e-mail on this topic, you made many statements similar to the
> following:
> 
> 
>>To the extent that there's any perceived danger of offensive
>>order-reversal, defensive truncation will be employed as a
>>countermeasure. 
>>
> 
> 	The thing is, the people who would be employing the "countermeasure" will
> not know whether the strategy they are attempting to counter has taken
> place, until after the election! (And even then they might not be sure!)
> And of course, at that point, it's very much too late to change whether or
> not you truncated.
> 	As you know, there are various examples where if voters truncate against
> a strategic threat that in fact does not exist to begin with, it can
> result in the election of the car crash candidate in itself. So voters
> can't always take lightly the decision to truncate against a candidate who
> may or may not be supported by strategic buryers.
> 	You seem to assume that a strategy of Dean voters to bury Kerry would
> involve someone in the Dean high command calling up various supporters and
> telling them to vote against their conscience. Then of course, the Kerry
> high command would find out about it, and call up the Dean high command
> and say "Hey! We know what you're up to! So if you don't tell your guys to
> vote sincerely, we'll tell our guys to truncate against Dean!" In which
> case it would be fairly cut and dry. 
> 	But in reality it doesn't have to happen like that. Voters for Dean and
> Kerry can all become *aware* of the fact that if they bury their second
> favorite, that it might help elect their favorite, and then again it might
> help elect their least favorite. Then, what happens on election day
> doesn't have to be determined by any coordinated strategy efforts. Before
> the vote no one will necessarily know who will try to bury and who won't.
> People who do intend to bury might decide not to mention it if they happen
> to be polled.
> 	What it may come down to is: To what extent do voters on each side have a
> propensity to gamble with burial strategies? To what extent do voters on
> each side expect voters on the other side to engage in burial strategies.
> 	The result of such a situation is unpredictable even if you know the
> sincere preference rankings, and that unpredictability is very dangerous.
> It is quite possible that successful burial will take place without anyone
> on the other side stopping it. It is also possible that a combination of
> mutual burial and mutual truncation (due to either aggressive or paranoid
> voting) could lead to the election of the car crash candidate. Both
> possibilities are chaotic and fundamentally undemocratic.
> 	The problem is just that there is no time to respond to the use of
> strategy. The purpose of extra rounds is precisely to provide the time and
> opportunity for such a response.
> 
> Mike also wrote:
> 
>>James A. also suggested some many-balloting (more than 2 ballotings) 
>>enhancements, but it seems to me that it would be much more difficult to 
>>propose to the public something that can need more than 2 ballotings.
>>
> 
> 	That is quite true. I think that 2 balloting wv Condorcet (2nd balloting
> only in the event of a cycle, and with the option for candidates to
> withdraw *in between* ballotings) is an extremely good proposal for public
> elections. This is what I would propose for a public election if anyone
> seriously asked me now.
> 	The multiple balloting thing would be nice, I think, but I agree that it
> is very unwieldy for very large-scale public use. 
> 	I think that in a two-round procedure, candidate withdrawal would play a
> more important role in effectively neutralizing strategy. The best way to
> assure that no abuses would be effective in the second round would be for
> a set of candidates to come to some sort of agreement whereby all but one
> of them drop out of the race before the second balloting, so that the
> opposition would not be able to use one of them to 'impale' the other one
> with a huge artificial defeat and leave the legitimate defeat of their own
> candidate as the defeat of least magnitude. There is still plenty of
> opportunity for cooperation to break down during the negotiation stage
> here, but at least it isn't possible for a strategic maneuver to steal the
> election completely by surprise, as it is in the single-balloting version.
> 	
> 	Although the two-round version is probably good for public elections,
> when you are voting in a reasonably small group, one where the cost of
> repeated elections is very minimal (for example a legislature, a club,
> etc.), I would definitely definitely recommend the multiple-round
> procedure over the two-round procedure. That is, take a Condorcet vote,
> and then follow it with a yes-or-no vote on the winner, whether the winner
> is a pure CW or a completed winner. This repeats until some option has won
> its yes-or-no vote, or until everyone gives up in frustration.
> 	This procedure has very real benefits over the 2 ballot procedure, and so
> it should always be used when the cost of additional ballotings is very
> low.
> 
> 	Going back to the two-ballot procedure, I still think that the second
> balloting should be a Condorcet balloting. I prefer a Condorcet balloting
> to an approval balloting here for all the reasons that I prefer Condorcet
> to approval in general.
> 
> 	And oh, Mike, my name is James Green-Armytage. "Green" isn't my middle
> name, but is rather a part of my surname. Hence "James A." is not an
> appropriate abbreviation for my name. If you feel the need to abbreviate
> it, I suggest "James G-A". There's nothing at all wrong with the name
> "James Armytage", except for the fact that it's not my name. (Other than
> that, I rather like it.) Green-Armytage was my father's surname, and also
> the surname of his father, and so on.
> 
> best,
> James

-- 
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  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
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