[Election-Methods] RELEASE: Instant Runoff Voting

[Aaron Armitage]

--- On Sun, 7/27/08, James Gilmour <jgilmour at globalnet.co.uk> wrote:

> 
> That is a consequence of your interpretation of how the
> voting system is supposed to work and what the voting
> system is supposed to
> be doing.  But that's not what IRV is about.  As I said
> in the previous message, the origins of IRV are in the
> Exhaustive Ballot,
> and in the Exhaustive Ballot there is no possibility of
> looking "at the entire ballot".  IRV is not about
> satisfying a set of
> criteria derived from social choice philosophy.
> 

Of course every reason you might offer for choosing one system over another is based on an idea of what a reasonable decision rule for making collective decisions in very large groups should look like. This is true for IRV advocate no less than advocates for other systems; where the system came from is beside the point, especially since most jurisdictions have never used the Exhaustive Ballot.

In an important respect, Condorcet is more natural than IRV: if a majority prefers Brad over Carter, this preference exists whether the voting system does anything with it, or even elicits enough information to determine that it exists. Condorcet simply discovers and applies this preference. IRV, on the other hand, elicits enough information to discover it exists, but may decide to ignore it based purely on procedural grounds. There are no good reasons for this, ever. "Core support" is a bogus reason: every time IRV chooses someone other than the plurality winner you're letting an overall majority trump a comparison of core supporters. But other times IRV will fail to do this, for reasons that simply don't exist apart from the system itself.