[EM] Why I think IRV isn't a serious alternative

[Greg]

That is incorrect. There have been tight (not "easy") elections where
IRV chose the Condorcet winner. The recent Pierce County Executive and
Assessor-Recorder races are two examples.

Also, there's actually a decent amount of real world ranking data
available. IRV data from San Francisco, Burlington, and Pierce County.
STV data from Cambridge and Ireland. Preferential presidential polls
from Ireland. And more. I'm in the process of making it all available
online in a uniform format.

Greg


On Wed, Nov 26, 2008 at 6:22 PM, Dave Ketchum <davek at clarityconnect.com> wrote:
> A good summary.  If we only cared about the easy ones Plurality would be
> good enough.
>
> DWK
>
> On Wed, 26 Nov 2008 08:43:42 -0500 Brian Olson wrote:
>>
>> On Nov 26, 2008, at 5:53 AM, Greg wrote:
>>
>>>> Oh, and actually it _is_ likely to be bad. See that first graph?  See
>>>> how
>>>> over thousands of simulated elections it gets lower social
>>>>  satisfaction?
>>>
>>>
>>> Brian, you're graphs are computer-generated elections that you made
>>> up. They aren't actual elections that took place in practice, which
>>> show a high unlikelihood of being bad. When your theory is a poor
>>> predictor of the data, it's time to change the theory, not insist the
>>> data must be different from what they are.
>>
>>
>> Given the substantial lack of data (pretty little real world rankings
>>  ballot data available), I think the simulations are still valid and
>>  interesting. The simulations explore a specific and small portion of  the
>> problem space in detail. I'm looking at races of N choices which  are
>> similarly valued by all the voters. It's a tight race. Actual  elections
>> haven't been that tight. But tight races are the interesting  ones. When
>> it's crunch time, those are the ones that matter. Almost  any method can
>> correctly determine the winner of a race that isn't  tight. So, IRV has
>> demonstrated in the real world that it can solve  easy problems. So what?
>> Why wait until it gets the wrong answer in a  real election to admit that
>> IRV can get the wrong answer? In matters  of public safety that would be
>> called a 'tombstone mentality'.
>
> --
>  davek at clarityconnect.com    people.clarityconnect.com/webpages3/davek
>  Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708   607-687-5026
>           Do to no one what you would not want done to you.
>                 If you want peace, work for justice.
>
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>