[EM] Majority Criterion/ Duverger

[Dgamble997 at aol.com]

Bart Ingles wrote in part:

>If this was a response to my post, then you ignored my point. Why do
>you consider "majority" to be more important that all other criteria?

I feel majority to be more important than all other criteria because the idea 
of majority rule is pretty central to democratic government. Generally 
speaking ( subject to constitutional safeguards to protect the rights of minorities 
) if a measure is approved by a majority in a binding referendum or a vote in 
a legislature it becomes law, if it rejected by a majority it does not. Since 
for a single office there can be only be a single winner, if one candidate is 
the clear and undisputed choice of a majority ( by which I mean the first 
choice of 50%+ of those who voted ) that candidate should win. This is my 
subjective opinion.

>> IRV, Condorcet, Bucklin and Plurality pass this criterion, Approval
>> and Borda fail it.

>That's debatable, depending how you determine compliance. If basing it
>on actual voted ballots, then Approval complies with the criterion (if
>only one candidate is approved on a majority of ballots, that candidate
>wins). If determining compliance based on sincere preference orders,
>then compliance depends on the voters casting sincere ballots.


It do not agree with the first half of this it is perfectly possible in an 
Approval election for two (or more) candidates to be approved by a majority of 
voters and for the candidate who under IRV, Plurality, Condorcet or Bucklin 
would have obtained 50% + of first preferences to lose. Whether this is caused by 
poor strategy ( setting your threshold too low ), lack of information, a wish 
to vote sincerely or a lack of voter interest in Approval strategy it 
nevertheless could happen.



>> Majority vote on two ballots (the electoral system of the French Third
>> and Fifth Republics) is extremely similar to IRV and top two runoff.

>In Duverger's text, he refers to a system where candidates withdraw
>after the first ballot, or where voters switch their votes to the
>stronger candidate. There was no explicit mention of "elimination". 
>But he does mention the Third and Fifth Republics. You say the system
>used there was "similar" to top-two runoff-- do you mean "identical", or
>were there differences?

The electoral system used in most elections during the Third Republic was 
single member constituencies, two rounds of voting. If no candidate won a 
majority at the first round a second round was held at which the candidate with the 
most votes won whether or not he (women did not obtain the vote in France until 
1946) obtained 50% of the vote. No candidates were eliminated and new 
candidates could enter the race at the second round. Generally less well placed 
candidates withdrew on the second round or lost support to stronger rivals.

For presidential elections in the Fifth Republic the system is top two 
run-off. For parliamentary elections if no candidate obtains a majority of the vote 
in the first round a second round is held in which the top two candidates and 
any other candidate who obtained the support of 12.5% of the electorate in the 
first round are  eligable to compete. The vast majority of second round 
contests are between two candidates.

>In any case, I don't deny that the pressures in favor of a two-party
>system are somewhat weaker with a runoff than with plain plurality, but
>the question is how much weaker. In fact the kind of multi-party system
>that Duverger sees arising from two ballots is not much different from a
>two-party system. To quote from the link above: 

>>> The sharpest difference with the system of proportional
>>> representation concerns electoral alliances. A coalition
>>> system par excellence, the two ballot regime can sometimes
>>> permit the formation of a dual system of alliances, introducing
>>> a sort of two-party system in the midst of a multi-party
>>> situation. This phenomenon was quite evident in France during
>>> the Third and the Fifth Republics, and in Germany from 1870 to 1914.    

Whilst the various components of the right wing bloc in France could be 
possibly be considered as one party, the left wing bloc definitely could not be 
considered as 'really a single party'. Until the mid 1970's the French Communist 
party publicly and often uncritically supported the Soviet Union (supporting 
such things as the 'normalisation' of the situation in Czechoslovakia in 1968). 
In certain significant areas it's attitudes and beliefs were completely 
different to those of its Socialist electoral allies.


David Gamble
    




    
    

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