[EM] IRV Failures

[Dave Ketchum]

Thanks, for putting together this level of detail is hard work.

On Tue, 08 Mar 2005 08:47:26 -0800 Bart Ingles wrote:
> Eric Gorr wrote:
> 
>> In a recent conversation with an IRV supporter I asked the question:
>>
>>  What cases would you accept as failure of IRV?
>>
>> They answered:
>>
>>  Where the general public (or a significant fraction of it) failed to
>>  accept the results as legitimate, or at least beyond question.  The
>>  2000 and 2004 Presidential elections are examples of failed elections.
>>  San Franciso's election was heralded as a success.
> 
> 
> I didn't know that 2004 was widely regarded as illegitimate.

The reports from Ohio read as solid evidence of failure.
> 
>> They also believe that IRV has never failed to produce a fully 
>> satisfactory result. Can anyone provide evidence to the contrary?
> 
> 
> I'm sure "satisfactory result" is already defined as "IRV winner", but 
> here goes:
> 
> (1) Australian lower house:  District elections are two-party races, 
> with Labour on the left and Liberal/National on the right, despite 
> whatever multiparty system exists in the PR-elected Senate.  Although a 
> two-party race doesn't provide much opportunity for an IIA or 
> monotonicity failure, some would view the absence of true multiparty 
> competition as the real failure.

Even Plurality does not have traction to make trouble in a two-party race.

PR is also not IRV.
> 
> Also, the prevalence of "how to vote" cards in Australia is often cited 
> as an IRV-induced problem.
> 
> (2) San Francisco 2004:  Of the four Supervisorial races tallied using 
> IRV, none elected a candidate with a majority of votes.  In one of the 
> races, the winner only received about 30% of the original vote.  The 
> main cause appears to be that voters were only allowed to rank three 
> choices, even though there were many more than three candidates.
> 
> In all four cases, the IRV winner agreed with the first-choice Plurality 
> tally.  Although IRV supporters are claiming that this is "positive"-- 
> that IRV didn' produce "unexpected" results-- it is probably a 
> predictable result of the three-choice limitation (the fewer choices 
> allowed, the closer the result will be to Plurality).  Also, the three 
> choice restriction would likely have masked any 
> Condorcet/IIA/monotonicity failures.

30% may be reasonable, given many candidates.

Having many candidates makes it hard to determine what the result SHOULD 
have been.

Combining many candidates with three-choice makes it harder to put 
together IRV-poison.  Still, as demonstrated in this thread, two-choice is 
enough if the voters make the right use of them.
> 
> (3) California gubernatorial race, 2002:  Although IRV wasn't used (it's 
> difficult to show actualy IRV failures when it hasn't been adopted), the 
> primary/general election was similar enough to a runoff to show what 
> would have happened under IRV.  The Republican primary featured Simon 
> and Riordan, while Davis ran opposed as the Democratic incumbent. 
> Riordan was eliminated in the primary, even though he was viewed as a 
> head-to-head favorite against either of the other two candidates.  Davis 
> won, setting  the stage for a successful recall election a year later.
> 
> Ironically, a similar situation arose in the 2003 recall election, with 
> McClintock and Schwarzenegger replacing Simon and Riordan.  Since this 
> was a single-round election, the need for strategy was obvious and 
> Republicans overwhelmingly backed the moderate candidate.

I read "Davis ran UNopposed" above.

Appears Plurality did fine here.  Sorta hard to make trouble, even with a 
zillion candidates, if you only have a couple ready to feed a cycle.

IF the two elections had been combined in 2002, with ranked ballots, there 
might have been ammunition for a cycle.
> 
> (4) Louisiana 1998(?) governor's race-- similar to California 2002.
-- 
  davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
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