[EM] IRV in action

[James Gilmour]

While I accept that IRV would reject some Condorcet winners, I have real concerns
about the political acceptability of the Condorcet outcome in some (very real)
circumstances and the effect of the voting system on electors' behaviour.

I have used the popular vote results of a real election, but I've reversed the two
largest figures to make a point.

Bush	50,996,064
Gore	50,456,167
Nader	 2,864,810

Please do not think this is an attack on the electoral college - that is a quite
separate issue.  I hope no one will be offended by my omission of all the other
candidates from this exercise.

If this were a popular vote FPTP election, Bush would win.  But if we assume Nader
supporters are closer to Gore than to Bush, some would say we should use IRV so
that the majority of voters could be represented.

Now we have to make assumptions (guesses) about how these same voters might vote
under a different voting system.

IRV1
Bush		50,996,064
Gore		50,456,167
Nader>Gore	 2,864,810

Nader is excluded and Gore wins.  Majority of voters represented.


IRV2
Bush		50,996,064
Gore>Nader	50,456,167
Nader>Gore	 2,864,810

As before, Nader is excluded and Gore wins.  Majority of voters represented.


IRV3
Bush>Nader	50,996,064
Gore>Nader	50,456,167
Nader>Gore	 2,864,810

As before, Nader is excluded and Gore wins.  Majority of voters represented.

BUT Nader was everyone's second choice and so this is not a properly
representative result.

Solution = Condorcet.  Result = Nader wins.
This makes good theoretical sense, which I fully understand, but I do not believe
it would be politically acceptable to the electors of the USA.

Were Condorcet ever to be adopted, I would predict that you would NEVER see the
voting pattern given at IRV3.  Once the major parties saw the effect of the
Condorcet system, their supporters would "bullet vote" only for the parties'
candidates.  So you would be back to the pattern at IRV1.   The "other side" might
win, but at least they wouldn't see their own chance denied almost automatically
in favour of a minor minority candidate.

I think the real world would be very different from the simulations commonly used
here to show the strengths and weaknesses of different voting systems.  My
conclusion would be that US electors would accept IRV but not Condorcet.

James