Talk:Tactical voting

From Wikipedia, the free encyclopedia

Congratulations to all involved - I think I started/contributed to this page (or one like it) some time ago: and now it is very much better than anything I could possibly have done.

Chris Baker

It can even be encouraged by political partys: If a party will not be strong enough by itself to form a government, but could form a coalition government if another party would pass the 5-percent-clause it will probably encourage tactical voting. (As did happen in Germany in 1984)

Okay, I understand how Germany's system works now, and see how this is tactical voting. I'll try to work this in on one of the PR pages. --DanKeshet

The section of 'Elite manipulation' is inappropriately titled and, to me at least, seems to be beside the point somewhat. Yes, people can be encouraged to vote tactically, but you seem to be making unnecessary value judgements here.

I didn't mean to make a value judgment there; I was just copying from the academic literature. (As a frequent campaign activist, I find it amusing that anybody would call me "elite".) I've changed it to something I hope will be more palatable.

Secondly, the article is a little too technical, too quickly. Without some mathematical background, I think you'd struggle to get much useful out of it. --Robert Merkel

I'll try to factor out the game-theory discussion into appropriate pages (like the G-S theorem page) and leave this page as an overview of how tactical voting occurs in real-life elections.
Incidentally, I've just started reading the academic literature on voting systems, and I'm now embarrassed at all the pages I've put up from the activist perspective. --DanKeshet

Contents

[edit] 2-1 Voting

It seems this important voting strategy, which merits inclusion in Wikipedia, doesn't fit in either strategic nomination, vote swapping, or electoral fusion:

2-for-1 Voting
by Bruce Ackerman
In November, Americans won't be casting their ballots directly for George Bush, John Kerry or Ralph Nader. From a constitutional point of view, they will be voting for competing slates of electors nominated in each state by the contenders. Legally speaking, the decisions made by these 538 members of the Electoral College determine the next president.
In the case of Mr. Bush and Mr. Kerry, electors will be named by each state's political parties. But Ralph Nader is running as an independent. When he petitions to get on the ballot in each state, he must name his own slate of electors. While he is free to nominate a distinctive slate of names, he can also propose the very same names that appear on the Kerry slate.
If he does, he will provide voters with a new degree of freedom. On Election Day, they will see a line on the ballot designating Ralph Nader's electors. But if voters choose the Nader line, they won't be wasting their ballot on a candidate with little chance of winning. Since Mr. Nader's slate would be the same as Mr. Kerry's, his voters would be providing additional support for the electors selected by the Democrats. If the Nader-Kerry total is a majority in any state, the victorious electors would be free to vote for Mr. Kerry.
This plan is consistent with the original understanding of the founders. When they created the Electoral College, they did not anticipate the rise of the party system; they expected voters to select community leaders who would make their own judgments when casting their ballots for the presidency. In designating Kerry electors rather than insisting on his own slate, Mr. Nader would be giving new meaning to this tradition that refused to view electors as simply vehicles of a candidate's will. In effect, he would be enabling his supporters to rank their choices: Mr. Nader first, Mr. Kerry second. (full article)

Should a new article be created? If so, how should it be named? Sir Paul 03:21, Jun 30, 2004 (UTC)

I would think this could go into the U.S. Electoral College article. There is a detailed discussion there now which this would fit well into. A brief summation of the general principle involved would also improve the broader Electoral College article. - toh 08:09, 2004 Nov 3 (UTC)

In the US the people who tried to fight the injustices of the electoral college and did vote swapping sites in the 2000 election banded together and now have a site, http://www.votepair.org

[edit] STV Tactical Voting

There is significant content in the Single Transferable Vote article about tactical voting in STV systems. Should it be moved here, or linked from here, or both? Scott Ritchie 20:43, 4 May 2005 (UTC)

[edit] Arrow's theorem

"Since Arrow's impossibility theorem proves that any voting system is arguably undemocratic in at least some case"

Could anyone please explain to me why this claim deserves to be here? I would take it off. Arrow and Gibbard-Satterthwaite show that any 'democratic' method is prone to manipulatable situations. Not that voting is un-democratic. It says life is complicated, not that life is wrong. mousomer 09:25, 24 October 2005 (UTC)

[edit] Borda vulnerability

"The Borda count has a both a strong compromising incentive and a large vulnerability to burying." Is this really true? If I'm not mistaken, then a large proportion of voters need to employ both in order to make a significant change - see Borda count#Potential for tactical voting. Common Man 11:13, 24 January 2006 (UTC)

Well, it's easier than you think. The crux of the matter is this: if you have one very favourable candidate (who's position is very strong), there is very little that tactical voting could do. The trouble is that the chances for that are not great. In most real life situations, you have several candidates, none of whom has a definite magority behind him. If you do the statistics, you could see that the most likely situations are where there is a tie or near tie between the candidates. It is exactly under these near-tie situations that tactical voting becomes relevant. mousomer 12:14, 28 January 2006 (UTC)

changed "vote swapping" in see also to "vote pairing" since that's where the vote swapping article has moved. Snowden666 18:18, 23 March 2006 (UTC)

[edit] explaining edit

I changed the line "that is, might not select the same outcome every time it is applied to the same set of ballots" to "that is, might not select the same outcome every time it is applied to the same set of voter prefrences" Because most methods will choose the same canidate If the ballots are the same, but with a diffrent amount canidates could choose a diffrent one.24.237.198.91 01:29, 23 November 2006 (UTC)

[edit] Brams and Herschbach

I see a reference which is quite non-standard (to say the least):

Brams, Herschbach, "The Mathematics of Elections" (sic?), Science (2000)

Apparently it was added a long time ago and never corrected or verified. I guess it refers to: "The Science of Elections" available online here:

http://www.sciencemag.org/cgi/content/summary/292/5521/1449

This reference is correctly listed in the following article of Wikipedia: http://en.wikipedia.org/wiki/Approval_voting

Best regards

Fioravante Patrone http://www.diptem.unige.it/patrone/default.htm

[edit] How to make manipulation computationally hard?

I think the following or similar reference should be added:

Universal Voting Protocol Tweaks to Make Manipulation Hard (2003), Vincent Conitzer, Tuomas Sandholm

http://citeseer.ist.psu.edu/conitzer03universal.html

http://www.cs.cmu.edu/~sandholm/voting_tweaks.ijcai03.pdf

From the "Abstract"

Voting is a general method for preference aggregation in multiagent settings, but seminal results have shown that all (nondictatorial) voting protocols are manipulable. One could try to avoid manipulation by using voting protocols where determining a beneficial manipulation is hard computationally. A number of recent papers study the complexity of manipulating existing protocols. This paper is the first work to take the next step of designing new protocols that are especially hard to manipulate. Rather than designing these new protocols from scratch, we instead show how to tweak existing protocols to make manipulation hard...

The protocols become NP-hard, #P-hard, or PSPACE-hard to manipulate...

These are the first results in voting settings where manipulation is in a higher complexity class than NP (presuming PSPACE ≠ NP).

I need a feedback about this. Or, if sure, please add such or similar reference...

--Y2y 11:06, 5 March 2007 (UTC)

[edit] 'Tactical' v 'Strategic'

It seems to me worthwhile to point out -- and I thought I once had, but perhaps not here -- that while 'strategic' and 'tactical' are usually used to distinguish behaviors in a disjoint set, here they counterintuitively mean the same thing, which is the topic of the article. If in fact everyone agrees that a) this is true and b) it's worth mentioning... where should it go? I'd think a parenthetical in the lede, but the lede diverges pretty rapidly right now from graf to graf...
--Baylink 19:23, 5 May 2007 (UTC)

[edit] Rewrite

I've put a rewrite tag on this article, because the overall tone appears to be somewhat negative. I've attempted to clean up the introduction, however the rest of the article needs work. Addhoc 16:49, 7 August 2007 (UTC)

Can you cite specific examples? It looks great to me. ←BenB4 16:36, 13 September 2007 (UTC)

[edit] Removal of Tactical Voting argument re Approval Voting.

Because Approval Voting can be understood as asking the voter to set an Approval cutoff, and the votes then express the "sincere" opinion of the voter with regard to that cutoff, the application of "tactical" voting as meaning an insincere vote for desired effect is problematic. There is no advantage to insincere voting in Approval.

Voting "strategy" is another matter. The thinking that there is tactical voting in Approval is based on an idea that there is some absolute Approval or Disapproval for candidates, whereas, in fact, approval is always a relative term, dependent upon the alternatives presented. So in a real election, the voter will make judgments as to where to set the Approval cutoff, dependent upon what the voter considers possible. A great deal of confusion is caused by the name "Approval Voting," and this was shown in what I removed. The voter may set the approval cutoff anywhere without being insincere. (Or, more accurately, if the voter votes insincerely, by reversing preferences, the voter harms his or her own expected outcome.) Abd 03:10, 7 October 2007 (UTC)

[edit] Contradiction with Approval voting

Tactical voting suggests that Approval voting is (nearly) immune to strategy, but approval voting says exactly the opposite. Both claims have references. Is there an expert in the house? Vectro 20:18, 8 October 2007 (UTC)

Approval voting is immune to deceptive claims (if a voter lies about their actual preferences then they hurt their chances of someone they prefer getting elected in all cases). However, Approval voting is VERY strategy dependent. For instance, if there are 3 candidates (A, B, C) and

40% of voters prefer A > B > C

29% of voters prefer B > C > A

31% of voters prefer C > B > A

Each voter needs to decide if they want to vote for their best candidate only, or vote for their top two candidates. A's supporters probably realize they are in the lead, and so will vote only for A. This puts people voting for C and B in a bind- as long as most of them vote for B and C, they will beat A. Most people voting for B or C will vote both, just to keep A out. The temptation exists, however, for just a few to vote for C only or B only- if their tactic succeeds, B will triumph over C (or vice versa). If too many succumb to the temptation, though, A will win despite being the worst choice for the majority of the people.

Thus, if I support B, I'm not sure whether voting (C and B) or just voting (B) will help me- I have two strategies to choose from, and have to pick one of them. I do know, however, that it's always in my interest to vote for B, and it's never in my interest to vote for A. (In a Plurality voting system, It may be in my best interest to vote for C instead of B, despite my preference for B).

Hopefully that explains why approval voting requires strategy, but never deception. Paladinwannabe2 19:38, 11 October 2007 (UTC)

Since we are defining tactical voting as 'voting insincerely' instead of 'voting strategically' Approval voting does not conflict with tactical voting. I will remove the contradiction flags. If we want to change the definition of tactical voting, then tactical voting could apply to approval voting. Paladinwannabe2 20:20, 11 October 2007 (UTC)

[edit] Definition of "Tactical voting" and application to Approval and other cardinal methods

From the introduction: "In voting systems, tactical voting (or strategic voting or sophisticated voting) occurs when a voter supports a candidate other than his or her sincere preference in order to prevent an undesirable outcome."

Now, how do we apply this definition to Approval? If we take the strict definition, without considering context, we would come up with the conclusion that if a voter adds a vote for any candidate other than the favorite, this is "tactical voting." However, that additional vote might be "sincere," and "sincere voting" is generally considered to be the opposite of "tactical voting." The definition is flawed, and the reason is that it was written for ranked methods, where "tactical voting" implies preference *reversal*. Warren Smith explores this issue on rangevoting.org, developing language to address a difference between preference reversal, which is fully insincere, preference expression, which is fully sincere, preference equality if the voter actually considers the candidates equal -- or possibly the preference is below some level of significance -- as also fully sincere, and preference submersion (my language), where the voter has a significant preference, would clearly choose one candidate over another in a direct contest, but votes for both for strategic reasons. I.e., the favorite doesn't have a snowball's chance in hell of getting elected!

Applying the definition as it stands to Approval takes us into some weird places. Suppose there is an election between A and B, and the voter intends to vote for A. Oops! Last minute, C announces a write-in campaign. If the voter votes for A but would actually prefer C, is this a "tactical vote"? Make this into an Approval election, and most voters that prefer A to B, and think C is unlikely to win, would probably vote for A and C, and consider this a sincere vote, even if the preference for C is strong. They will look at the election in terms of what is realistically possible, and make a choice among the realistic choices. If, in fact, both A and C gain a majority, they might regret their vote for A. This contingency, though, by the conditions of the problem, is rare.

Assuming that equal ranking in the presence of a preference is "tactical voting," then, leads to problems. It defines what the voter may consider a perfectly sincere vote, thinking of Approval as a matter of setting an approval cutoff, and the voter sincerely set that cutoff, as a "tactical vote," and this is then used in arguments to claim that Approval encourages "insincere voting." Which is, ahem, bovine refuse.

In the contrary direction, some of the same people will look at Approval and consider it vulnerable to tactical manipulation by small groups of voters, based on the idea that these voters actually approve of A and B, but vote only for their favorite, A, and then that favorite wins, whereas if these voters had voted "sincerely," B would have won.

Yet, in this case, this block of voters simply voted for their favorite. How is this "tactical voting"? It seems that there are people, even academics, playing with the definition to suit their theses.

When Brams claims that Approval is not vulnerable to tactical voting, he is claiming that *preference reversal* is never rewarded. Whereas, when the concept of tactical voting is applied to ranked systems, preference reversal is always the case.

The definition in the article *can* be read as requiring preference reversal. We simply read "supports a candidate other than his sincere preference" to mean "raises in rank or rating above his sincere preference." However, clearly, the definition wasn't written to contemplate equal ranking. Same problem with the Majority criterion.

I intend to do some more research and edit the article accordingly, comment invited, and, especially, any reliable sources on the definition of tactical voting that aren't already in the article. --Abd (talk) 17:34, 19 January 2008 (UTC)

I agree that the lead description of tactical/strategic voting is poorly written. The logical application of that description to various voting systems is unclear. There is room for improvement. However, it may be unrealistic to expect to find a common definition or a universally applicable definition in the literature.
There are at least two core issues here: what is tactical/strategic voting and what is sincere voting. Some definitions of the former are dependent on the latter. In any case, addressing the issue of sincere voting in the general case is needed on Wikipedia and this article is an appropriate starting point. The approval voting and range voting articles deserve a discussion of sincere voting specific to those voting systems.
(It is important to not transform Brams' claims about tactical/strategic approval voting by dropping the restrictions and qualifications that he attached to those claims.)
DCary (talk) 20:24, 19 January 2008 (UTC)
That's correct. However, the article places in opposition Brams' claims and those of the other authors (they "disagree"). Are they really in opposition, or are they using different definitions and conditions? Further, there is a problem here. The citation to the article in Public Choice is to an abstract that does not state what the WP article states. Presumably it's taken from the text of the Public Choice article. But that isn't easily accessible. Presumably, the person who inserted the material here has access to the actual article; therefore I'm asking for quotation of sufficient text to establish the context and meaning of the Public Choice quotation.
There is another problem that the Brams article is not actually cited, though I may be able to find it (I think I may have seen it somewhere). The source should be properly cited in our article.
--Abd (talk) 21:27, 19 January 2008 (UTC)
Okay, it always pays to check. There was an editorial in Science by Brams and Herschbach on Approval Voting.[1] It does not make the claim in the text of this article. Don't you love arguments based on what one side didn't say? However, that editorial does note some well-known problems with ranked methods, but it doesn't make the comparative statement. I think what Brams has written elsewhere was the basis, so the article is incorrect and should definitely be fixed. I don't yet know what to fix it *to*, yet! --Abd (talk) 21:35, 19 January 2008 (UTC)
Ooops! That was a summary, it was so long I thought it was the editoral. At least that's how it looks right now. Sometimes Brams has copies of articles elsewhere, I might be able to find it. --Abd (talk) 21:40, 19 January 2008 (UTC)

[edit] Expressive Voting

There has been a considerable academic literature develop in the past decade on "Expressive Voting" -- but I don't find it covered in Wikipedia at all. It might, at least, merit a section in this article on Strategic/Tactical Voting. I did a quick search on Google Scholar and found this paper, with a serviceable definition, at the top of the list as "most cited" (it indicated there had been 68 citations of this particular article in the scholarly literature). From the abstract:

"There are two rival accounts of rational voting ...: the mainstream instrumental account, that sees the vote as a revelation of preference over possible electoral outcomes, essentially analogous to a market choice; and the expressive account, that sees the vote as expressing support for one or other electoral options, rather like cheering at a football match. This paper attempts to lay out some of the implications of the expressive account ..." Brennan, G; A. Hamlin (1998). "Expressive voting and electoral equilibrium" (in English). Public Choice 95 (1): 149-175. Kluwer. ISSN 0048-5829. [Useful overview of the concept of expressive voting. Lay summary]. 

I think this idea is a bit different than what is reflected in the article today, yet may be considered a form of tactical voting. What do others think? N2e (talk) 16:35, 12 February 2008 (UTC)

What you describe is interesting and related to voting, but it does not seem a part of tactical voting. See the first sentence of the article: "In voting systems, tactical voting (or strategic voting or sophisticated voting) occurs when a voter supports a candidate other than his or her sincere preference in order to prevent an undesirable outcome."
It seems that expressive voting would be where a voter votes for a candidate they really would prefer, but perhaps has no chance to actually prevail in an election. Maybe a new article is needed. —Preceding unsigned comment added by 71.163.232.181 (talk) 15:08, 1 March 2008 (UTC)