[EM] possible improved IRV method

Eric Gorr eric at ericgorr.net
Wed Jun 28 17:48:40 PDT 2006


Jonathan Lundell wrote:
> At 5:12 PM -0500 6/28/06, eric at ericgorr.net wrote:
>> Quoting Jonathan Lundell <jlundell at pobox.com>:
>>
>>>
>>>  IRV's problem with ignoring later preferences and not always finding
>>>  a Condorcet winner is a direct consequence of the way it avoids
>>>  Condorcet's problem with encouraging insincere voting.
>>
>> On what basis do you claim that a good Condorcet Method would 
>> encourage insincere voting?
>>
>> I have yet to see any convincing arguments that it does. Most of the 
>> attempts tend to center around a single group of voters attempting to 
>> manipulate the election to their advantage. The fundamental flaws with 
>> these particular arguments is that they assume that (a) no other 
>> groups will attempt counter-strategies,
> 
> Of course they will, which makes matters worse.
> 
>> (b) that a single group of voters will even be capable of obtaining an 
>> accurate enough picture to figure out how to change their votes - 
>> accuracy they would need appears to be far greater then one is able to 
>> obtain with a scientific survey of voter opinion and
> 
> On the contrary. All you really need is a fairly reliable sense of who 
> the front-runners are. The recent Democratic primary for governor in 
> California is a case in point. In a relatively large field, there were 
> only two candidates, Angelides and Westly, with any chance at all at the 
> nomination, and polls had them fairly close, with six other candidates 
> in the low single digits. It required no more knowledge about the 
> election than that for Angelides supporters to be motivated to bury 
> Westly, and vice versa, had it been a Condorcet election.

You are welcome to provide a realistic example with actual vote counts.

>> (c) the fact that if multiple groups of voters are involved in 
>> insincere voting when a Condorcet Method is used that the ultimate 
>> resolution becomes quite chaotic and the worst possible winner may be 
>> selected.
> 
> Which makes matters worse, not better, for Condorcet methods.

On the contrary...see below.

>> It is the potential for selected the least favorite choice that causes 
>> me to believe that a good Condorcet Method actually encourages sincere 
>> voting.
> 
> Wheels within wheels. If I believe that other voters are that rational, 
> and will forego burying my candidate in fear of electing a less-favored 
> candidate, then I have more motivation to use burying myself.

And again, if everyone is attempting to counter manipulations and 
counter counter manipulations, the Condorcet Election methods become 
chaotic and anyone could be the winner.

However, this is problem can largely be solved through education.

> Regardless, your argument illustrates one of my points. You strongly 
> prefer Condorcet voting because (at least in part) you minimize its 
> flaws. But it's a faith-based minimization that assumes a model of voter 
> behavior that, near as I can tell, has little evidence to back it up.

I do not minimize it's flaws...it certainly has flaws and some rather 
annoying ones. For example, I do wish it passed the Participation 
Criterion, was not chaotic when groups of voters would attempt to 
manipulate the outcome via strategic voting, etc.

However, this "flaw" you bring up has yet to be shown to exist based on 
what I have seen and you have yet to provide any evidence that it does 
exist.






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