[EM] Need IRV examples; voting show

[Olli Salmi]

At 19:13 +0200 8.12.2002, James Gilmour wrote:
>> Do you mean to say that in Approval a vote counts towards the election of
>> several candidates?
>
>No - one vote can count towards the election only of one candidate.  But
>the voter
>may have several votes being counted simultaneously.

A fine point. I don't think I understand it.

>> Do I have more power if I approve of several candidates?
>
>That almost certainly depends on your definition of 'power'.

I had joint stock companies in mind, where you have the more votes the more
stock you own.

>> Do I have most power if I approve all of them?
>
>No - irrespective of your definition of 'power'.  To vote for all
>candidates has
>the same effect on the outcome as not voting for any of them.  In terms of the
>purpose of the election, the effect is identical - nil.

Good, I agree, we have some common ground then.

Let's now move on and beam ourselves to the school where the idea of STV
was born. We are again conducting an election by standing behind our
favourite candidate, but this time only one boy is to be elected. Just to
make sure, the teacher has asked us to fill in a ballot paper, an ordinary
STV ballot. But he has also, rather autocratically, imposed two new rules.

First, when a candidate is in danger of being eliminated, we are obliged to
move into his line, if we have marked a preference for him on our ballot --
you know, siding with the underdog and all that. The contest of elimination
is between the two lowest candidates, and we are allowed to abandon our
higher preferences temporarily without endangering them.

Second, at this point, in connection with elimination, we are not allowed
to express a preference. If we have voted for both the last and the second
to the last candidate, we have to step back and abstain until the
elimination has been decided, even if one of the candididates is our first
preference. Or we could cast half a vote for each candidate, which gives
the same net result. With this rule we have to be a bit careful who we vote
for. We don't want to express a preference for the big bully because we
wouldn't be able to help to eliminate him.

When it has been decided who is to be eliminated, we will strike out the
eliminated candidate from our ballot paper and move again to the line of
our favourite candidate, if he hasn't been eliminated. The election will
continue in the same way until all candidates but one have been eliminated.
Elimination is used even when there are only two candidates left, meaning
that we have to abstain if we have both on our ballot.

Because we are physically standing in line, the voter cannot have several
votes being counted simultaneously. Do you agree?

This kind of election should find the Approval winner sequentially, if I've
got it right. The order of preferences is of course irrelevant and so is
the order in which eliminations are decided.

Olli Salmi


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