[EM] IRV vs Plurality (Dave Ketchum)

[Kathy Dopp]

> Message: 3
> Date: Fri, 15 Jan 2010 22:05:58 -0500
> From: Dave Ketchum <davek at clarityconnect.com>
> To: Juho <juho4880 at yahoo.co.uk>
>
> On Jan 15, 2010, at 7:46 PM, Juho wrote:
>> On Jan 14, 2010, at 2:13 AM, Dave Ketchum wrote:
>>> On Jan 13, 2010, at 4:49 AM, Juho wrote:
>>>> On Jan 13, 2010, at 9:14 AM, robert bristow-johnson wrote:
>>>>
>>>>> it still is a curiosity to me how, historically, some leaders and
>>>>> proponents of election reform thunked up the idea to have a
>>>>> ranked-order ballot and then took that good idea and married it
>>>>> to the IRV protocol.  with the 200 year old Condorcet idea in
>>>>> existence, why would they do that?
>>>>
>>>> 1) The basic idea of IRV is in some sense natural. It is like a
>>>> street fight. The weakest players are regularly kicked out and
>>>> they must give up. I'm not saying that this would lead to good
>>>> results but at least this game is understandable to most people.
>>>> Condorcet on the other hand is more like a mathematical equation,

Yet Condorcet is simple to count and precinct-summable, monotonic, and
treats all voters' votes equally, unlike IRV/STV which is virtually
impossible to manually count, requires a mind-boggling number of piles
and subpiles to count it and requires that all late-counted ballots
are ready to count centrally, or the entire long tedious process has
to be restarted.

>>>> and the details of the most complex Condorcet variants may be too
>>>> much for most voters. Here I'm not saying that each voter (and not
>>>> even each legislator) should understand all the details of their
>>>> voting system. The basic Condorcet winner rule is however a simple
>>>> enough principle to be explained to all. But it may be that IRV is
>>>> easier to market (to the legislators and voters) from this point
>>>> of view.

The organization promoting IRV/STV is very well-funded and invests a
lot of capital into highly misleading local advertising campaigns in
order to promote its adoption.  I could send this list some
information on that if anyone is interested.  I don't think that any
group promoting a fair, equitable, auditable alternative method like
Condorcet or others has put forth such a well-funded campaign have
they?

>>>
>>> When there is a CW in Condorcet, the CW has won in comparison with
>>> each other candidate.  While a few may like X or Z enough better to
>>> have given such top ranking, the fact that all the voters together
>>> prefer the CW over each other should count, and does with Condorcet.
>>>
>>> Else there is a cycle in Condorcet.  Perhaps the following Minimum
>>> Margins Method Condorcet variant should be used to establish
>>> Condorcet's preferability over other methods.  Then let other
>>> variants compete with this one before finally deciding which to use.
>>>
>>> Minimum Margins Method:  Consider the cycle, such as A>B>C>A, and
>>> the margins that create it, such as 60A>30B, 40B>20C, 21C>20A.
>>> Delete the weakest margins as many times as needed to destroy the
>>> cycle - in this case A becoming the CW (note that if one C>A voter
>>> had voted A>C in  this election, A would have become CW with no
>>> cycle).

Great idea. Is this Dave Ketchum speaking above?  Very simple and
logically coherent plan.  Thanks for sharing.  Could it be possible
that this plan would ever not work? (I.e. same margins?)

>>
>> When I see this kind of scenarios I'm always tempted to ask the
>> question if it is necessary to limit the scope to the top cycle
>> members or if one can allow also the others win (when the cyclic
>> opinions in the top cycle are strong). I find also that approach to
>> be a working solution for many election types (although many have
>> indicated that they disagree with this).
>>
> Note that this method breaks the cycle at the point where the smallest
> number of ballots being voted differently would have broken the cycle.
>
> Note that weaker candidates are unlikely to get enough votes to be
> part of a cycle - being weak they get few high rank votes.

Yes, one could certainly say that this allows the top cycle to prevail
by breaking the weakest link where weakest is defined as the smallest
margin in this case.  This minimum margins method is so logically
correct and fair.

>>>>
>>>> 2) IRV is easier to count manually. Condorcet gets quite tedious

Whomever said this obviously hasn't ever counted any IRV or STV
elections manually in a contest with a substantial number of
candidates and voters.  Condorcet is orders of magnitude simpler to
count than is IRV because there can never be more than n x n tallies
to tally in each precinct and those tallies are precinct-summable,
whereas IRV requires tallying

n*(n-1)*(n-2) + n(n-1) +n tallies for each precinct even if the voter
is only allowed to rank three choices - a huge number of tallies as
the number of candidates grows large and a much larger amount as the
number of allowed rankings goes up - for each precinct, at least if
the method is made precinct-summable rather than using a huge number
of sorting piles which I haven't yet derived the formulas for and have
no plans to do so.

The reason it takes cities over a month to manually count IRV/STV
elections in large cities in practice when they don't have computer
equipment attests to its utter complexity when trying to accurately
count it manually.  A little test would be to create a semi-complex
election contest and use say, even just half of the possible
permutations that IRV/STV can produce and see how many test subjects
can figure out how to accurately manually count the votes.  The only
reason it didn't take Minneapolis that long was because the voter
turnout in Minneapolis' first IRV/STV election was astronomically
depressed (low) and the incumbant winning candidates had a majority of
first choice votes so it was won by a simple plurality count.

>>>> to count manually when the number of candidates and voters goes
>>>> up. One can use some tricks and shortcuts to speed up manual

Condorcet is SO much easier and quicker and simpler to count than IRV
if one simply tallies one n x n matrix for each precinct and sums the
corresponding positions for all the precincts.  No need to wait for
all the absentee and provisional ballots, no need for centralized
counting, no need to sort and resort ballots into dozens of piles of
ballots, or even worse with STV keep track of which portion of which
ballot goes into which pile (tearing or cutting up the ballots would
help in that manual counting nightmare.)


>>>> Condorcet counting but IRV probably still beats it from this point
>>>> of view. Manual counting was the only way to count for a long
>>>> time. Nowadays we have computers and Condorcet tabulation should
>>>> thus be no problem at all (at least in places where computers are
>>>> available). But this is one reason why IRV has taken an early lead.
>>>
>>> When an election district has only one polling place, life is simple.

Yes. Another point against IRV/STV is no scalability of manual
counting. Condorcet is infinitely scalable since it is as simple to
manually count dozens or hundreds of precincts as it is to count one,
without moving all the ballots to one central location.

>>>
>>> When the district is a state or city, life is more complex for each
>>> method.

For IRV/STV, but not for precinct-summable methods like Condorcet or
all the various other precinct-summable methods.

Imagine sending all your ballots nationwide to DC for manual counting
to check the outcome of a Presidential election. We'll simply let the
GW administration, for instance, count the results in his own IRV
election!

Truly, I cannot imagine a more insane method of counting rank choice
ballots than IRV/STV when one begins to consider the practicalities of
election administration.

That minimum margin idea for resolving Condorcet cycles is neat, if
one wants to use rank choice ballots.



-- 

Kathy Dopp

Town of Colonie, NY 12304
phone 518-952-4030
cell 518-505-0220

http://utahcountvotes.org
http://electionmathematics.org
http://kathydopp.com/serendipity/

Realities Mar Instant Runoff Voting
http://electionmathematics.org/ucvAnalysis/US/RCV-IRV/InstantRunoffVotingFlaws.pdf

Voters Have Reason to Worry
http://utahcountvotes.org/UT/UtahCountVotes-ThadHall-Response.pdf

Checking election outcome accuracy --- Post-election audit sampling
http://electionmathematics.org/em-audits/US/PEAuditSamplingMethods.pdf