[EM] Why I think IRV isn't a serious alternative 2

Terry Bouricius terryb at burlingtontelecom.net
Wed Dec 24 17:06:51 PST 2008


Abd wrote about "center squeeze":
The problem happens with
reasonable frequency with Top Two Runoff, and the principles are the
same. *In this way,* IRV simulates TTR, though, in fact, it is a
little better in choosing among the remaining two. IRV would not have
elected Le Pen. But it missed the very clear, and broadly supported,
Jospin, who would have won against Chirac, and not by a small margin.
If Jospin had gotten 1% more of the vote, the runoff would have been
between Chirac and Jospin, the voter turnout would have been lower
because of lower preference strength, but I'd have predicted, from
what's known, 70% or more of the vote for Jospin.

It sounds as if you are saying IRV would have missed electing Jospin over 
Le Pen and Chirac...but perhaps by "it" you mean two round runoffs??? If 
you want to promote two-round runoffs over IRV, you shouldn't use the 
example of the French election, because it shows the exact opposite of 
what you seem to claim here. That French presidential election underscores 
how IRV also is better than runoffs that reduce the field to two after the 
first count. Extremist Jean Marie Le Pen only gained the runoff with 17 
percent of the vote (barely more than his share in past elections) because 
the center-left split its 40 percent-plus pool of votes among several 
candidates. Under IRV, by reducing the field gradually, the center-left 
vote would have coalesced behind prime minister Lionel Jospin, putting him 
well ahead of Le Pen and within striking range of Jacques Chirac. This is 
an example of how IRV can avoid the center squeeze that is far more 
probable with your favored two-round runoff method.

Another shortcoming of two-round elections is the sharply lower voter 
participation (primarily among lower income voters) typical in one of the 
rounds of a two election system. I know you have written favorably about 
such drop off in voter turnout as an effective method of "compromise" 
(voters who don't care enough stay home). I disagree.

Terry Bouricius

----- Original Message ----- 
From: "Abd ul-Rahman Lomax" <abd at lomaxdesign.com>
To: "Terry Bouricius" <terryb at burlingtontelecom.net>; "Dave Ketchum" 
<davek at clarityconnect.com>; "Election Methods Mailing List" 
<election-methods at electorama.com>
Sent: Wednesday, December 24, 2008 7:02 PM
Subject: Re: [EM] Why I think IRV isn't a serious alternative 2

At 08:56 PM 12/22/2008, Terry Bouricius wrote:
>I think you make a common semantic manipulation about the nature of a
>Condorcet winner (particularly in a "weak" CW example) by using the term
>"wins by a majority."

He wouldn't be the one who invented this practice, Terry.

>  In fact, each of the separate and distinct pairwise
>"majorities" may consist largely of different voters, rather than any
>solid majority.

That's correct, with truncation. This is why it's an important
reform, one long ago introduced into the U.S. in progressive
jurisdictions, to require a majority of ballots contain a vote for
the winner, at least in a primary that can elect if there is a
majority. The big error that was made, and it was made with Bucklin
as a runoff substitute -- it was also sold that way, as well as with
IRV -- was to imagine that, somehow, these preferential voting
systems were going to manufacture a "majority."

>  This is why I think the Mutual-Majority Criterion is a
>more useful criterion. In a crowded field, a weak CW may be a
>little-considered candidate that every voter ranks next to last.

Sure. But wait a minute! "Every voter ranks next to last." Ain't
gonna happen unless "every voter" ranks all the candidates. Under
voluntary ranking systems, that represents "every ballot containing a
vote for the Condorcet winner." Consider the case that this is RCV,
three ranks. That's a strong showing! But it *also* isn't going to
happen in public elections, except possibly with exceeding rarity
under unusual conditions. The biggest factor in voting patterns in
public elections is probably name recognition. A Condorcet winner
with high name recognition is also going to get a substantial number
of votes. This is not a "little-considered" candidate if everyone
uses one of their three ranks for the candidate.

Terrill, it's pretty obvious to me that the decision to support IRV
in the U.S. was made for strategic reasons, not because the system is
actually superior to other options. IRV is probably inferior
(different result being a worse result) in probably one out of ten
nonpartisan elections or so, just compared to top two runoff, not to
mention better systems (in my view, real runoff voting has a huge
advantage, such that it's possible that TTR, with write-ins allowed
-- as is the case in some U.S. jurisdictions -- is better even than
Range. And what have you and your friends been replacing with IRV?
Plurality? No. Top Two Runoff, vulnerable because of (1) widespread
ignorance about the difference between IRV and TTR, and (2) an
alleged -- and possibly spurious -- cost savings.

FairVote's first "victory" was the San Jose measure that allowed IRV,
in 1998. The ballot arguments were flat-our wrong. They essentially
would only be correct with full ranking, which is a Bad Idea in the
U.S. and is the reason why Oklahoma Bucklin was ruled
unconstitutional. It wasn't the additive method, it was the mandatory
full ranking. The ballot analysis by the "impartial" county counsel
-- who apparently swallowed the propaganda -- and, of course, the Pro
argument by Steve Chessin et al, very specifically misrepresented the
majority issue, using "ballots" instead of the somewhat vaguer
"votes" in the similar San Francisco situation.

IRV *functionally, in nonpartisan elections*, is Plurality. The
difference must exist, sometimes, when an election is close enough,
but it is rare enough that we haven't seen it yet in the U.S. in over
thirty such elections. And since, if it does occur, the vote is
likely to be quite close, it's quite unclear that IRV would be enough
better than Plurality *in that context* to make it worthwhile. TTR
*is* better, clearly, in probably one out of ten elections.

I'm waiting for you to realize just how much of a mistake was
made.... You and FairVote have been damaging U.S. democracy,
replacing the only method which is known, in practice, to encourage
strong multiparty systems, with IRV, which doesn't. That method, Top
Two Runoff could be made better by using a better preferential voting
system in the primary, and submitting, to a runoff, ambiguous results
(such as majority failure, but there are other possible situations,
such as a multiple majority in an additive system like Bucklin -- 
though, here, there is good precedent for choosing the candidate with
the most votes). IRV avoids runoffs by discarding the majority
requirement through a trick definition. Bucklin doesn't follow that
definition, if there is a majority in Bucklin it is not a trick, all
the ballots are included and counted. So Bucklin will show "majority
failure" when IRV can conceal it, to those who don't pay attention,
by only considering the last-round votes, meaning that many voters,
who did vote and cast legitimate votes, and who did not necessarily
truncate, don't count, it is as if they did not vote.

>   The
>phrase "wins by a majority" creates the image in the reader's mind of a
>happy satisfied group of voters (that is more than half of the electors),
>who would feel gratified by this election outcome. In fact, in a weak CW
>situation, every single voter could feel the outcome was horrible if the
>CW is declared elected.

If so, they were totally foolish to rank that candidate. Ranking a
candidate should be reserved for acceptable candidates, mediocre *at
the worst*. Not horrible. And this is what voters actually do with
Optional Preferential Voting. Only at most something like a third of
the voters add additional preferences, they only add them when they
think them worthy of being elected.

Terrill, you are making up arguments to defend the indefensible:
"Condorcet winner" means that every other candidate would lose in a
pairwise election with that winner. (If not, voters are using odd
strategy, or perhaps they are forced to rank all candidates, as in
Australia, so equal-bottom is not available.) Borda detects the
problem, giving the next-to-last candidate only a very weak vote,
and, indeed, this is one reason why Borda fails the Condorcet
Criterion.... The problem with Borda is that it doesn't allow
differences in preference strength to be shown, using the candidate
sequence as a very rough approximation of preference strength. But
that's fixed with Range, which is otherwise, really, the same as Borda.

Now, using hypothetical scenarios that would be impossible in real
elections under real conditions is a means that can be used to
confuse and deceive the unsophisticated. Ask an expert if the system
is vulnerable to this, the answer will be Yes. Only if the expert
answers with more than what the question addressed will the inquirer
learn the truth. "Yes, but this scenario is, in practice, impossible."

Yet when much more common situations, such as Center Squeeze, are
raised with IRV, the answer is very different. "It's rare, prove that
it happens!" Center Squeeze, though, is a very well known problem
with sequential elimination, it's remarkable that Robert's Rules of
Order chooses to mention it as a problem. The problem happens with
reasonable frequency with Top Two Runoff, and the principles are the
same. *In this way,* IRV simulates TTR, though, in fact, it is a
little better in choosing among the remaining two. IRV would not have
elected Le Pen. But it missed the very clear, and broadly supported,
Jospin, who would have won against Chirac, and not by a small margin.
If Jospin had gotten 1% more of the vote, the runoff would have been
between Chirac and Jospin, the voter turnout would have been lower
because of lower preference strength, but I'd have predicted, from
what's known, 70% or more of the vote for Jospin.

These are real situations, not theoretical scenarios where voters
vote some totally stupid strategy.

>  Using a phrase like "wins by a majority" creates
>the false impression that a majority of voters favor this candidate OVER
>THE FIELD of other candidates AS A WHOLE, whereas NO SUCH MAJORITY
>necessarily exist for there to be a Condorcet winner.

That's correct. And that is why one submits such elections to a real
runoff of some kind, which is the only way to get a majority. It
almost always does. It only fails when there are write-in candidacies
allowed. It's possible by using better methods for the primary and
runoff, to allow write-ins without harm, where a real majority would
be found in the vast majority of elections. Want to make that a
guarantee, it must be an unlimited series of elections, no
eliminations. And the only way I know of to do that is to elect
deliberatively, and only Asset Voting can pull this off on a large scale.

But Top Two Runoff approaches it, except for Center Squeeze, which
can be fixed by using a better method for the primary. How about a
runoff between a Condorcet winner and a first preference winner? But
there should be further process whenever acceptance of the leader is
not shown on a majority of ballots. That's Robert's Rules, you know,
even though you argued derisively against it for a time.

Limiting it to the top two is a compromise, a poor one with a
plurality primary, in some cases. Better methods could make a better
choice of top two. I've suggested that, in Range, when the Range
winner isn't approved by a majority (as explicitly defined on the
ballots), or when there is a candidate who beats the Range winner
pairwise, using preference analysis, there be a runoff. This, from
strong theoretical grounds including simulations, will improve
results over Range, which otherwise is the leader with single
ballots. That specific combination (range/pairwise) hasn't been
simulated, but top two Range has.

>  The concept of
>Condorcet constructs many distinct majorities, who may be at odds, and
>none of which actually need to like this Condorcet winner.

Sure. If there is full ranking. But, you know full well, truncation
is the norm. RCV doesn't even allow more than three ranks to be
expressed, and still there is a lot of truncation. I really should
look at those San Francisco ballot images. What I want to see is how
many voters don't add any ranked votes to votes for the frontrunners.
My guess is that *lots* of them don't. If they do, those are
candidates that the voter actually wants to support in some way, not
realizing, perhaps, that the vote will never be counted.

Isn't this a bit disturbing? Quite likely, most of the votes cast in
an IRV election aren't ever counted. That's not true with American
Preferential Voting, Bucklin.

Watch for arguments against IRV to start using the fact that Bucklin
was invented here in America and was, indeed, known as the American 

>  I am not
>arguing that the concept of "Condorcet winner" is not a legitimate
>criterion, just that its normative value is artificially heightened by
>saying the candidate "wins by a majority" when no such actual solid
>majority needs to exist.

That's correct, by the way. However, if there is full ranking, and
based on the preferences and votes as expressed on the ballot, it
does indicate that the winner would, indeed, win by a majority
against any other single candidate.

It's true, though, that if there were an actual TT runoff, the voters
would give sharper consideration to the two candidates on the runoff
ballot. Voters change their minds. Some of the bottom-rank Condorcet
votes may have been strategic, faced with the reality, the voters
might reconsider.

I assume one thing: voters do, almost entirely, vote sincerely in
IRV. It appears that, historically, they also did this with Bucklin.
The effect of preference strength on voting patterns has largely been
neglected, instead, a concern for "Later No Harm" has been expressed,
as if this were some universal voter concern. In fact, it depends on
preference strength. If the voter has little preference strength for
the Favorite/2nd preference pair, the voter is quite likely to add a
ranked vote. If it is strong, not, unless the voter is clear that the
Favorite hasn't a prayer, and even some of these will still truncate.
That's what they do with Plurality (vote contrary to interest in
outcome), that's what they do with IRV, when they can, and they
likewise did it with Bucklin.

Voters with strong preference, and particularly if their favorite is
a frontrunner, are unlikely to add additional preferences unless you
coerce them, and coerced votes are the kind that could show the weak
preference being described for a Condorcet winner. Solution: don't
coerce voters!

More information about the Election-Methods mailing list