# [Election-Methods] Dopp: 1. "Does not solve the "spoiler " problem except in special cases."

Steve Eppley SEppley at alumni.caltech.edu
Sun Jun 15 12:48:11 PDT 2008

```Hi,

Most analyses of spoiling (and voters' strategizing to avoid spoiling)
narrowly focus on the candidates who reached the general election
ballot. The much bigger spoiling problem is during the nomination
process, when candidates choose not to run in the general election due
to concern they will make the outcome worse if they run. (Example:
McCain in 2000, who chose not to run for President as an independent
after failing to be nominated by the Republican party.) It's a
deterrence of competition. It explains why parties each nominate only
one candidate per office and it explains why few politicians who care
about the outcome join minor parties.

That sort of analysis falsely makes spoiling in major elections appear
rare, regardless of the voting method (even plurality rule). When
analysis properly includes the deterrence of competition, the spoiling
problem is rampant with plurality rule, top two runoff, instant runoff
and approval.

The deterrence of competition is the worse problem, in my opinion. The
effect tends to be only two parties that have a chance to win, each
party nominating only one candidate per office, using badly flawed
procedures (primary elections, for example) to decide which one
candidate the party will nominate.

Furthermore, the two parties tend to become polarized. One name that's
been given the cause of the polarization is the "center-squeeze effect."
That is, candidates who want to win avoid moderate positions because
candidates at those positions will tend to lose due to being sandwiched
between the candidates to the "left" and the candidate to the "right." A
much older analysis was the model of "two candidates under risk of 3rd
candidate entry" (given plurality rule). That analysis was more
realistic than the conditions in the median voter theorem. The median
voter theorem leads to the prediction that when there are exactly two
candidates competing on one issue dimension, they will both try to take
the position of the median voter, given plurality rule or any voting
method that reduces to majority rule when there are 2 candidates. The
prediction of the more realistic analysis where more than 2 candidates
can compete is that neither of the 2 major candidates will compete at
the median position, since if either does, a 3rd candidate at a position
a little further from the median can enter the race and win.

On the matter of polarization, Instant Runoff looks as bad to me as
plurality rule and top two runoff.

Polarization of two big parties may create a false impression that the
voters too are polarized. It may also increase actual polarization among
voters, since voters won't hear as many moderate arguments.

One reason some people are clamoring to replace plurality rule with
Instant Runoff appears to be occasional election outcomes like Bush in
2000, when Nader was a spoiler. Most Nader voters preferred Gore over
Bush, so Gore would have won if Florida had used Instant Runoff. The
trouble with the argument is that in a close spoiled election, the
number of voters who prefer the spoiled outcome is a large minority;
there won't be a consensus that the spoiled outcome is worse. When the
winner of a spoiled plurality rule election has a large minority of the
votes, given only the votes it doesn't matter to the well-being of
society which of the top two wins. It only appears to matter, since the
combination of the spoiling and the polarization leads to a big
difference in policy choices. The closeness of the vote totals means one
cannot tell, given only the votes, which set of policy choices is better
for society, so in my opinion the ever-present problem of nomination
deterrence is much worse than occasional spoiling in general elections.

P.S. - I presume some people will say the 1992 Clinton-Bush-Perot
election was spoiled, since some polls indicated Bush would have won if
Perot hadn't run. In other words, that Perot took more votes from Bush
than from Clinton. That may be. However, there was apparently a majority
cycle, according to a poll by Gary Jacobson of UC San Diego. If Perot
had dropped out, Bush would have won. If Clinton had dropped out, Perot
would have won. If Bush had dropped out, Clinton would have won. So
which one was the spoiler? Furthermore, the smallest of the three
majorities was the majority who preferred Bush over Clinton. That means
Clinton would have won anyway given the Condorcetian methods most
popular among the members of this email list, if Jacobsen's numbers were
right.

P.P.S. - Kathy Dopp's request for arguments about Instant Runoff was
expressed in terms of support and opposition. Those terms are absolutist
shorthands that omit the key information about what the item is being
compared against. By the same reasoning that a voter could oppose
Clinton (when compared against Obama) and support Clinton (when compared
against McCain), someone could both support and oppose Instant Runoff.
How should someone who believes Instant Runoff is slightly better than
plurality rule and Condorcet is much better than Instant Runoff respond

Regards,
Steve Eppley
----------------------------------------
Abd ul-Rahman Lomax wrote:
> At 11:50 PM 6/11/2008, Greg wrote:
>> The FairVote document that debunks Dopp's claims is available at:
>> http://www.fairvote.org/dopp
>
> Or, more accurately, "attempts to debunk." Ms. Dopp is a voting
> security expert, not an election methods expert, and some of her
> statements can be flawed, especially if one focuses on technical
> details. I'm going to break this response into a series of posts on
> each separate topic, because otherwise it gets *way* too large.
>
> This first section is a good example.
>
>> De-Bunking Kathy Dopp's 15 Flaws of Instant Runoff Voting
>> 1. Dopp: "Does not solve the "spoiler" problem except in special
>> cases…."
>>
>> Dopp has her “special cases” reversed. In fact, IRV solves the
>> spoiler problem in virtually all likely U.S. partisan elections.
>
> Which does not contradict Dopp's statement. The problem is that
> "special cases" implies "only rare cases," but, technically, IRV *may*
> reduce the spoiler effect in ... a special case, i.e., when a minor
> candidate is not in range of winning, but due to vote splitting,
> causes the overall preferred major candidate to lose to one less
> preferred. It does not deal well with the center-squeeze effect, where
> there are three candidates in range of winning, and this is, I
> believe, what Ms. Dopp refers to.
>
> Notice the "special case" in the anonymous response: it isn't "IRV"
> solves the spoiler problem. There are three hedges: "virtually all,"
> "likely," and "partisan." The most operative of these restrictions is
> "partisan." Whoever wrote this -- I suspect Rob Richie, and he is
> certainly aware of this interchanges, since he commented on it on
> Wikipedia, in Talk for the article on Instant=-runoff voting -- is
> quite sophisticated. IRV, in the absence of the kind of vote transfers
> that take place in partisan elections (where the large majority of
> vote transfers from one candidate may favor a single other candidate),
> does little to solve the remaining "spoiler effect," center squeeze.
> It is debatable whether or not center squeeze should be called a
> spoiler effect. I've done so in the past, but the phenomenon is
> different, and I'd be happy with confining the term "spoiler" to refer
> to minor candidates, not candidates who can actually win an election
> or come close. In which case, indeed, Ms.Dopp's statement, as made,
> would be faulty.
>
> But she is, in fact, talking about center squeeze, which is a real
> problem, one of the two that are so notable that Robert's Rules
> mentions them.
>
> Further, the response wants us to think of all U.S. elections when, in
> fact, IRV is generally being proposed as a replacement for real runoff
> elections. Which do not show the spoiler effect in anywhere near the
> same strength as seen with Plurality. And where that spoiler effect
> *is* in effect in runoff voting, IRV may well fail to resolve the
> problem; indeed, usually it will.
>
> What has been missed in most discussion of the issue is that IRV, as
> proposed in the U.S., is a plurality method. Don't confuse this with
> Majority Criterion compliance. Plurality methods will elect a
> candidate even though a majority of voters haven't voted for that
> candidate, that's a simple description of it. Jurisdictions have
> runoff voting because they value finding a majority vote for the
> winner, and top-two runoff actually accomplishes this. The truth is
> that it is impossible to guarantee a majority vote in a single ballot;
> it is even impossible with a limited series of ballots, except that
> with top-two runoff, because of the ballot design and voter habits, a
> majority will almost always be found. (Most top-two implementations
> allow write-in votes, so a maintained preference of voters in the
> first election for an "eliminated candidate" can allow that candidate
> to win. I've never seen it, but, usually, when the Condorcet winner is
> eliminated, the preference strength, apparently, is not enough to
> motivate voters to turn out and vote write-in. In other words, Top-Two
> runoff, in real practice, works quite well, much better than
> simplistic voting systems theory might predict.
>
>> Whenever a third party or independent candidate is unlikely to be one
>> of the top vote-getters (true in over 99% of U.S. elections), IRV
>> eliminates the spoiler problem completely.
>
> Actually, no. If you look at Australia, in the places where ranking
> all candidates is optional, there is a lot of plumping. So there is
> still a spoiler effect. FairVote has always implied that the
> Australians use a uniform method, but, in fact, some places use STV
> with an absolute majority requirement, and they guarantee that
> requirement by voiding all ballots that don't fully rank the
> candidates, and other places use Optional Preferential Voting -- which
> is what is proposed for the U.S. -- and plumping -- we call it bullet
> voting -- is common and, apparently, increasing, according to Antony
> Green of ABC. Naturally, the majority requirement for OPV is relaxed
> to "a majority of ballots containing votes for remaining candidates."
> That's a plurality method. Regular STV, PV, is a majority method, but
> it coerces the votes. Take your pick. (Or require a majority, as
> jurisdictions which are using runoff voting do, and then use
> preferential voting, of whatever kind, or Approval Voting, to more
> efficiently find majorities and avoid *some* runoffs.
>
>
>> If a third party grows to the point that its candidates out-poll
>> major party candidates, another issue that is related to the spoiler
>> problem can occasionally arise. This is where supporters of a third
>> party candidate may worry that by supporting their favorite
>> candidate, they risk causing their less-preferred compromise choice
>> to be eliminated from the final runoff, leading to the election of
>> their least-preferred choice. In other words, the issue of whether to
>> vote for your favorite choice, or to rank your compromise choice
>> first can resurface in this unique circumstance. But this is
>> extremely rare and no different than a candidate in a party’s
>> political primary arguing “Vote for me because I am more electable in
>> the general election.
>
> This argument presents center-squeeze as if it is a strategic voting
> problem, when, in fact, center-squeeze is the problem, and strategic
> voting is how some knowledgeable voters might attempt to fix it.
>
> The problem is not rare if there are three major candidates. In that
> situation, there is no candidate that we would ordinarily think of as
> a "third party candidate," which always refers to a minor candidate.
> Three major candidates can occur much more commonly in nonpartisan
> elections than in partisan ones, in a two-party system. And, remember,
> IRV is mostly being proposed at this time for nonpartisan elections!
> That is what it is being used for in San Francisco.
>
> (Continued with the next point, Dopp: 2. “Requires centralized vote
> counting procedures at the state-level…")
> ----
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> info

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