Problems with Condorcet

David Marsay djmarsay at dera.gov.uk
Wed Aug 5 05:38:48 PDT 1998


I support most variations of Condorcet, but share Bart's concerns 
(below).

I have previously suggested that ballots should allow voters to 
express some equal first and equal second rankings, and then use 
Condorcet, but ignoring rankings after the second.

It seems to me that this overcomes the worst of  Bart's concerns 
about FPTP and the worst of his concerns about Condorcet, which are 
really concerns about the lesser rankings.

If Condorcet is a good method for counting votes, then surely my 
proposal can inherit some of its virtue? I admit that it is not 
ideal, but it is surely better than FPTP?

Comments, please.

P.S.

I have the view that there is probably no one ideal method. Hence it
might be a good idea to allow voters to rate options (cf Mike Saari's
postings) but only use the limited rankings as above. The full
data could be used for post-election analysis to guide any changes to
the system.


> Date:          Tue, 04 Aug 1998 15:58:34 -0700
> From:          bartman <bartman at netgate.net>
> Subject:       Problems with Condorcet

> While Condorcet-type elections favor a compromise candidates in a closed
> setting such as a parliament (as favored in Roberts Rules) where
> candidates are relatively well-known peers of the voters themselves,
> Condorcet is not well suited for use in large public elections.  Given
> the realities of political advertising and voter psychology, full
> ranking can not be relied on to give meaningful enough results to
> support pairwise counting.
> 
> For example, a vote which ranks a major candidate last may simply mean
> that he is perceived as the greatest threat to the other major
> candidate.  This is reinforced by negative advertising by major
> candidates, who tend to demonize their main opponents while ignoring the
> rest.  This does not necessarily mean he is an extremist or unqualified;
> it may simply mean he is the second most popular. 
> 
> Middle-rankings are also suspect, since not all candidates are equally
> well known.  A vote which ranks a candidate somewhere in the middle may
> mean the candidate is an acceptable compromise, or it may simply mean he
> is an unknown who is not perceived as a threat to a more favored
> candidate.  Even if he is a reasonable compromise in one sense, he may
> be an extremist in other areas.  He may also be otherwise unqualified
> for some reason which could easily be overlooked, since a voter is not
> likely to use the same care in selecting lower-ranked candidates that he
> would use for his first choice.
> 
> If anyone wants to assert that the above scenarios will be rare
> exceptions, I would like to see the arguement.  Personally, I would
> suspect that these scenarios would be just as likely as not; the real
> problem is that there is no way to predict one way or the other.  As a
> result, the only rankings with relatively unambiguous meaning would be
> the first, or possibly the first couple.  This may not matter much with
> IRO, since the lowest rankings are the least likely to be used, but it
> would render Condorcet the equivalent of pulling names out of a hat.
> 
> While limiting the number of rankings may rule out some aesthetically
> "ideal" election methods, at least the remaining possibilities are
> simpler to implement.  Besides, there are other (probably more
> important) reasons to replace FPTP elections than the prospect of
> occasionally electing a 3rd-party candidate.  These should be of major
> concern to anyone interested in electing "compromise candidates".  Some
> examples:
> 
> 1)  When an FPTP vote is "spoiled", the winner is the candidate that the
> 3rd party voters would have voted *against* in a runoff (i.e. worst
> possible outcome).
> 
> 2)  In FPTP there is a tendency for centrist 3rd parties to push the
> major parties away from the center by devaluing swing votes (in a
> two-man race, swing votes are worth twice as much as "fringe" votes,
> since in gaining a swing voter, the opponent loses the same voter, for a
> net difference of two votes).  When a third candidate absorbs a large
> number of centrist votes, the major candidates have less reason to
> compete with each other for these votes and instead pay more attention
> to extremist voters.  This is in addition to any shift of the major
> candidates' bases of support due to displacement by the other parties.
> 
> Bart Ingles
> 
> 
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Sorry folks, but apparently I have to do this. :-(
The views expressed above are entirely those of the writer
and do not represent the views, policy or understanding of
any other person or official body.



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