[EM] The Hippopotamus Logic

donald at mich.com donald at mich.com
Wed Nov 6 09:27:01 PST 1996

Dear List, the following exchange of messages took place:

Mike:>>>If a full majority of all the voters indicate that they'd rather
>>>have A than B, then if we choose A or B, it should be A.
>>>Condorcet's method is the only proposed method [that] respects that
>>>principle, meaning that it will never unnecessarily violate it.

Donald:>>Would you show me an example of IRO violating the rule of majority?

Steve: >The 46/20/34 example shows IRO violating it.  We've discussed this
>already, but here goes again:
>   46:ABC
>   20:B
>   34:CBA
>A majority (54) indicated they'd rather elect B than A, yet IRO
>elects A.  If there's some principle which makes you think this
>is a "necessary" violation, I'd like to hear it.

Donald: Candidate B does not have fifty-four votes. Candidate B only has
twenty votes - it is right there in your example in black and white 20:B
Candidate A has forty-six votes and candidate C has thirty-four votes -
there is a difference between votes and selections - this is suppose to be
an example of a Instant-Run-off election - not Condercet.

When you say "A majority (54) indicated they'd rather elect B than A .."
you are creating a STANDARD. Now the question is: How was this standard
created - answer: you used Condorcet. You used Condorcet to create a
standard in which you used to compare Instant-Run-off. The next step is to
compare Condorcet to this "Standard" - and Condorcet should meet the
standard - surprise! surprise!

You cannot do this Steve. We've discussed this already, but here goes
again. When we compare apples to oranges we cannot use the apple nor the
orange as a standard to compare each. That would be like saying: Condoret
is best because Condorcet is more like Condorcet than any other method -
this is more of the Hippopotamus logic.

This example you have presented is not the worst example used to support
Condorcet but it is bad on three accounts.
   One: It is loaded to favor one candidate
   Two: It is not realistic
 Three: These election votes would not come from a Instant-Run-off election.

This example is loaded to favor candidate B with more than twice the number
of selections over either of the other two candidates - when we consider
only the first two selections. The first two are the only selections of any
importance with a three candidate race. You have given 46 selections to
candidate A - you have given 34 selections to candidate C - BUT! you  have
given 100 selections to candidate B - and then you state that B should be
the winner - surprise! - surprise!

The second way in which this example is bad is that you have the 46 voters
of candidate A voting lockstep all for the same candidate B on the second
selection. Likewise you have the 34 voters of candidate C doing the same.
This is not realistic. This would never happen. I do not know how these
voters would vote their second selections but I am going to split them in
half so I can get on with my side of this discussion. 23AB  23AC   20B
17CA  17CB

This is getting better but this is not the votes from an Instant-Run-off
election - which is the third bad thing about your example. The voters of
the last place candidate in the polls would not omit making a second
selection in an Instant-Run-off election. So - I am going to give second
selections to the twenty votes of candidate B and I am going to split these
selections evenly between A and C - just to be fair. 23AB  23AC  10BA  10BC
17CA  17CB

Now this is an example of an Instant-Run-off election that would "Mollify"
even me. Under run-off rules candidate A is still the winner. Just for the
fun of it - let us see who wins using Condorcet.

                    A and B           A and C          B and C
                    Pairing           Pairing          Pairing
23AB                23A               23A              23B
23AC                23A               23A                  23C
     10BA               10B           10A              10B
     10BC               10B               10C          10B
          17CA      17A                   17C              17C
          17CB          17B               17C              17C
--------------      --------          -------          -------
46A  20B  34C       63A 37B           56A 44C          43B 57C

Look at these results! - A beats B and C  Surprise! Surprise!
Candidate A is the winner. Candidate B is last - same as Instant-Run-off.
Seems like when the example is realistic and not loaded the Condorcet
results become the same as Instant-Run-off - the more things change the
more they remain the same.

If someone were to show me your example and ask me: "What can you say about
this election by only seeing and knowing this first tally of the votes?" I
can tell a few things about the example by just looking at it.
   One: The election was not an Instant-Run-off election
   Two: The election is going to use Condorcet as the single-winner method
 Three: This is the first time that these voters voted in a Condorcet election.

I can make these three statements because one group of voters refused to
make any more than one selection. They are being clever. This is the way to
manipulate a Condorcet election - have your group refuse to support any
other candidates on the second selection - but you hope the other voters
will support your candidate on their second selections. Sometinmes it will
work - you may be able to pull it off - your candidate may win it all.

When the next election for this race comes around more of the voters will
be clever. The votes of the next election may look like the following:
          40A  2AB  4AC  20B  30C  2CA  2CB
Candidate B no longer has 100 selections - candidate B is now a loser -
like he should have been at the start of this example.

The people have the right to know before an election which single-winner
method will be used to crunch the numbers because the selections in a
Condorcet election are different from the selections in an Instant-Run-off
election. The selections have different weights and meanings. In Condorcet
the selections are votes and can be used against the voters' first
selection - in Instant-Run-off only the first selection has a vote.

As more people know about the Condorcet method most of them will only make
one selection. The Condorcet election becomes a plurality election - the
more things change the more they remain the same.

This is the big hurdle that Condorcet most likely can not get over - if
people refuse to make a second selection the Condorcet method goes down the
Now you could have a law passed forcing people to make the required
selections under fear that a Condorcet Technocrat will use a big RED marker
to void their ballot.

Instant-Run-off does not have this problem. As people understand the method
they will see that it is to their advantage to make more than one


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