[EM] Margins vs. Winning Votes

[Dave Ketchum]

On Thu, 28 Jul 2005 02:31:01 +0300 Juho Laatu wrote:

> On Jul 26, 2005, at 23:41, Dave Ketchum wrote:
> 
> ...
> 
>> My comparison of methods:
> 
> 
> Nice description of strategies and summary of methods, thanks.
> 
>>      Condorcet margins - like above, but less apt to pick best liked.
> 
> 
> Why less apt? I find the choices of margins quite ok.
> 
>>      Approval - its backers like to brag, but it is not that simple - 
>> unlike Condorcet and IRV, voters CANNOT say:  I prefer Nader but, only 
>> if I cannot have Nader, give me Kerry as better than Bush.
>>      Ratings - I choke on the complexity as worse than the above.
> 

Note, "give me Kerry as better than Bush" has earned me a lot of static - 
it is my desire as a voter, but much else can affect whether I get that 
result.

> 
> I think there is a trade-off between expressiveness and strategies. 
> Rating based methods are nice since they can express so much, but they 
> are too vulnerable to strategies and therefore unusable in most 
> (contentious) elections. Approval, as you note, lacks expressiveness. 
> But strategies are not that big of a problem. Pair-wise methods and IRV 
> are somewhere in between when it comes to expressiveness. Pair-wise 
> methods are more expressive than IRV. I hope their problems with 
> strategies are not too bad and their expressiveness could be used in 
> elections for the benefit of all.


We seem to disagree as to where the tradeoff is.

Starting in a Plurality world, what do the other islands look like?
      Condorcet:  The average voter, most of the time, is not interested. 
  Bullet voting is acceptable and often adequate.  When a race inspires 
interest, then picking out the candidates of interest and lining them up 
according to desirability requires nothing new as to kinds of thinking. 
Even ranking candidates as equals is no strain (beyond learning to mark 
that on a ballot) for those with such a desire.
      IRV starts the same as Condorcet.  IRV's problem with ignoring data 
only comes up when it messes up an election.  Seems to me we argue about 
voters ranking candidates as equals, but that is not a big deal.
      Approval, likewise, will tolerate bullet voting.  As with Condorcet, 
voters soon want to approve multiple candidates - and must be told they 
CAN, ONLY, rank all approved candidates equally.

For all of the above the concepts are simple to explain to voters, who can 
move into taking more advantage at their chosen pace.

Primaries are essential for parties in a Plurality world.  Move to a 
different island and primaries are expendable - but the voters must get 
past bullet voting to survive this (think of a party with two competing 
candidates - a primary would sort this out - without a primary you must 
get past bullet voting for a single voter to vote for more than one).

Then we come to ratings and the more exotic methods that get discussed in 
EM.  How much must the average voter learn to survive the related 
suspicions when on the same island, let alone taking advantage?


> 
>> I do not see how this example promotes margins:
>>      Under wv the plotters achieved their goals.  NOT that I approve, 
>> for they were only guessing as to what other voters might do.
>>      Under margins they claimed to prefer the LEAST liked candidate 
>> over one they actually preferred.  Fact that their strategy elected 
>> the least liked is not a success to celebrate - more a warning to be 
>> cautious when considering strategy.
> 
> 
> The reason why I think the example speaks in favour of margins is that 
> the results of the strategy brought no benefits to the strategic voters 
> (who seemed to try some sort of a burial strategy but were mistaken and 
> failed). Therefore margins (at least in this case) encourage people to 
> simply vote sincerely and forget strategies. (while winning votes 
> encouraged plotters to vote strategically and also gave results to them)


Not ready to accept this example as determining value of wv vs margins. 
The example was one structure - other structures could read differently.

> 
> BR,
> Juho

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  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
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