[EM] 02/02/02 - Alexander, don't get stuck in a `Time Warp':

[Adam Tarr]

First off, why did you feel the need to be so condescending in that 
message?  Mr. Small never said, "I think those folks at the CVD are 
fools."  He never said, "I'm special and they should change because I want 
them to."  He asks a legitimate question... should he, "become a member of 
CVD and try to persuade them to change?"  Nothing disrespectful abut 
it.  He has not been privy to a long and drawn-out debate that may have 
motivated your harsh response.  Yet you chose to put him down for the 
length of your response.  Really, try keep it professional when others have 
treated you in kind.  If you manage to get into an ugly argument with Mr. 
Ossipoff, then at least you won't be the sole participant.

Now... as for the actual election methods... I do hesitate in trying since 
you have surely heard and disregarded most of the good arguments against 
IRV many times.  But perhaps I can strike a chord that others missed, so I 
will make an effort.  Please note that I am only criticizing IRV for 
single-winner elections; it works fine (in its STV form) for multi-winner 
elections with sufficiently large (i.e. many seats) districts.

First off, let me refer you to a web site that summarizes things.  You can 
follow links provided in the body of the message to get more information on 
problems with IRV.

http://www.electionmethods.org/IRVproblems.htm

Now that that is out of the way, I can jump to a specific example.  Now, I 
agree that IRV works fine at removing the "spoiler" problem.  That is, as 
long as two parties remain dominant, IRV prevents minor third parties from 
interfering.  This is why and how it has "worked" in the single winner 
Australian elections; it has kept the third party down.  Every voting 
reform (except maybe Borda) does a good job of preventing the spoiler 
problem.  The problem with IRV arises when the third party is no longer 
guaranteed to lose.

Imagine, for a moment, that I am heading to the polls to vote for President 
of the USA in 2000.  Only in this reality, Nader is far more popular in the 
polls than he was... basically all three candidates are rather close, with 
Bush slightly ahead of Nader, who is slightly ahead of Gore.  But all three 
are very close.  The question is simple... who do I vote for if I support 
Nader, but I like Gore more than Bush?  (obviously not an unlikely situation).

In Condorcet voting, the choice is obvious.  I vote Nader, Gore, Bush in 
that order.  If Nader manages to out-place both Gore and Bush, I get my top 
choice (Nader).  If Nader does not win, I have voted for Gore in the 
Gore-Bush election.  An easy vote to cast.  With Condorcet voting, Gore is 
extremely likely to win, since he is the middle, compromise choice of the 
three candidates.  (Note: the specter of three-way ties is one some like to 
bring up, but can you think of a realistic situation where it will 
happen?  In this scenario, it requires a score of people voting 
Bush-Nader-Gore or a similarly illogical combination.  If someone tried to 
"force" a tie by voting insincerely like this, they would be far more 
likely to shoot themselves in the foot by electing the person they pushed 
up in their rankings.  Three way ties require a very strange and 
non-intuitive set of preferences by the electorate.  When they exist, 
there's usually a good reason and they shouldn't be ignored.)

In Approval voting, I clearly vote for Nader, and then I decide whether to 
vote for Gore.  If I think that Nader is likely to lose to Bush, then I 
vote Gore as well.  Not a very easy decision, but at least an obvious 
one.  Gore is again likely to win the election, although it's not for sure.

In Borda Count... well I don't like Borda Count very much, but it can work 
well in this case.  I vote Nader, Gore, Bush in that order.  Gore probably 
gets a lot of second place votes from the supporters of the other two 
candidates, and wins the election.

In IRV... how you vote depends on how much you trust the polls.  If you 
assume (it seems reasonable) that the Gore voters will split between Nader 
and Bush about evenly, then it looks like Bush will win the election, since 
he's a little ahead of Nader in the polls.  But maybe the Gore voters will 
break over to Nader enough to pass Bush in the second round, or maybe Nader 
is actually ahead and the polls are off.  So you could either cross your 
fingers and vote Nader, Gore, Bush, or you could switch your top two and 
vote Gore, Nader, Bush.  That way, you could help beat your top choice 
(Nader) but make sure all the Nader voters join up with Gore and beat 
Bush.  You would be hedging your bets.  But what if Nader would have beaten 
Bush in the runoff?  Things are close enough that it's very possible.  You 
have to vote based on how accurate you think the polls are, and how evenly 
you think Gore voters will split.  Not an easy decision.

Furthermore, if Bush voters think that Bush is a safe bet to make the last 
round, but Nader is likely to lose a close race to Gore (maybe because of 
those insincere Nader voters), they can actually make Bush win the election 
by putting him at the bottom of their list behind Nader.  Basically, they 
are giving their votes to Nader in the hopes that they make Gore lose in 
the first round, get half the Gore voters in return and get Bush to win the 
runoff.  A risky vote, and a bizarre result, but quite possible.  This is 
the problem with IRV in close multi-candidate races: things become erratic 
and voters have all sorts of non-intuitive options on how to "play the 
game" to get the best result.

The above was not a far-fetched example.  It doesn't require strange 
initial preferences of a very specific set of percentages.  It only 
requires a three-way race with some uncertainty in the outcome.  This is 
what will happen in the USA if a third party ever challenges the other 
two.  If IRV is implemented, then perhaps we will be "lucky" like the 
voters in the 1 seat/district Australian House or in the too-small Maltese 
districts, and we will remain in a two-party duopoly.  Or perhaps we would 
end up with unpredictable and erratic elections like the one I have 
described above.  But personally, I would prefer to have stable elections 
that made for real multi-party competition in single-winner elections, like 
Condorcet would provide.

If you choose to respond, please do address the example and explain why IRV 
will succeed where the other voting methods fail.

-Adam

Adam Tarr, Ph.D. Student
Purdue University
School of Electrical and Computer Engineering
atarr at purdue.edu
(765)743-7287