[EM] IRV vs Plurality

[Terry Bouricius]

Juho,

That was a good summary of IRV and Condorcet dynamics, and how their 
different weaknesses might be perceived by a citizenry.  I would like to 
add one more to your list. Different voting systems provide different 
incentives for candidate behavior and campaigns and thus voter 
information.

It has been argued that IRV tends to reduce negative campaigning, or makes 
campaigns overly bland (depending on your stance), because in addition to 
seeking first choices, candidates want to reach out to the supporters of 
other candidates. However, with Condorcet rules, it is possible for a 
candidate to win in a crowded field while receiving no first choices at 
all. There haven't been any real-world high-stakes elections to know for 
certain what effect this might have, but it would seem reasonable to 
expect candidates to avoid taking stands on controversial issues. 
Candidates would have an incentive to campaign just using a vacant theme 
of "I promise to listen to YOU."

IRV seems to strike a reasonable balance between appealing for a strong 
core of supporters (the only requirement  in a plurality election with 
many candidates) and also developing broad appeal as an alternate choice. 
Condorcet tips towards the broad appeal alone. Condorcet would seem to 
encourage candidates to simply avoid alienating anybody, with little need 
to develop strong core support.

Thus, I wonder if Condorcet would "dumb down" campaigns to the point that 
voters would have even less information to evaluate candidates by.

A candidate who flew below the radar, such that no voters had any negative 
opinions of the person, just might win, even if finishing in last place in 
terms of first choices. I suspect the voters wouldn't be happy, even 
though that was the logical result of their ballots.

Terry Bouricius


----- Original Message ----- 
From: "Juho" <juho4880 at yahoo.co.uk>
To: "EM Methods" <election-methods at lists.electorama.com>
Sent: Wednesday, January 13, 2010 4:49 AM
Subject: Re: [EM] IRV vs Plurality


On Jan 13, 2010, at 9:14 AM, robert bristow-johnson wrote:

> it still is a curiosity to me how, historically, some leaders and
> proponents of election reform thunked up the idea to have a ranked-
> order ballot and then took that good idea and married it to the IRV
> protocol.  with the 200 year old Condorcet idea in existence, why
> would they do that?

1) The basic idea of IRV is in some sense natural. It is like a street
fight. The weakest players are regularly kicked out and they must give
up. I'm not saying that this would lead to good results but at least
this game is understandable to most people. Condorcet on the other
hand is more like a mathematical equation, and the details of the most
complex Condorcet variants may be too much for most voters. Here I'm
not saying that each voter (and not even each legislator) should
understand all the details of their voting system. The basic Condorcet
winner rule is however a simple enough principle to be explained to
all. But it may be that IRV is easier to market (to the legislators
and voters) from this point of view.

2) IRV is easier to count manually. Condorcet gets quite tedious to
count manually when the number of candidates and voters goes up. One
can use some tricks and shortcuts to speed up manual Condorcet
counting but IRV probably still beats it from this point of view.
Manual counting was the only way to count for a long time. Nowadays we
have computers and Condorcet tabulation should thus be no problem at
all (at least in places where computers are available). But this is
one reason why IRV has taken an early lead.

3) Large parties are typically in a key role when electoral reforms
are made. Election method experts within those parties may well have
found out that IRV tends to favour large parties. In addition to
trying to improve the society the best way they can, political parties
and people within them also tend to think that they are the ones who
are right and therefore the society would benefit of just them being
in power and getting more votes and more seats. The parties and their
representatives may also have other more selfish drivers behind their
interest to grab as large share of the power as possible :-). IRV thus
seems to maintain the power of the current strongest players better
than Condorcet does, and that may mean some bias towards IRV.

4) The problems of different election methods may appear only later. A
superficial understanding of IRV reveals first its positive features.
Like in Burlington the negative features may be understood only after
something negative happens in real elections. This applies also to
Condorcet. On that side one may however live in the hope that the
problems are rare enough and not easy to take advantage of so that
sincere voting and good results would be dominant. The point is that
IRV may be taken into use first (see other points above and below)
without understanding what problems might emerge later. And once it
has been taken into use it may well stay in use for a long time
(electoral reforms are not made every year, people have already gotten
used to the method, having to change the method could be seen by the
society/legislators as a failure/embarrassment, and people/parties who
were elected based on those rules and are strong in that system may be
reluctant to change the rules).

5) Both IRV and Condorcet have some weak spots that can be attacked.
As you point out the weak spots of IRV may well be worse than those of
Condorcet methods (for most typical use cases in politics). Different
problems may have different weight in different political
environments. For example in countries with strong two-party tradition
and single party government some Condorcet properties like the
possibility of electing candidates that do not have strong first
preference support in the ballots may work against it (both in the
case that one does not want the system to change and in the case that
one wants to renew the system). Also strategic voting and fraud
related problems (like later no harm, burial, precinct counting) may
be seen in different light in different societies, e.g. in countries
where strategic voting is the norm vs. in ones where sincere voting is
the norm. One may thus have/develop points of view where Condorcet
looks worse than IRV (I guess it could also be worse for some uses in
some societies from some points of view).

Juho


P.S. One more reason is that Condorcet promoters seem to be lazier
that IRV promoters :-). Condorcet has made some progress in the
academic circles but not yet in politics.








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