[EM] Manipulability stats for (some) poll methods

[Closed Limelike Curves]

Michael—you're right that it means favorite-burial (cutting the "head" off
a ballot). The term is quite old, though (older than "favorite betrayal" or
"favorite burial" I believe)
<https://www.cambridge.org/core/product/identifier/S0003055400194481/type/journal_article>
.

On Sun, Apr 28, 2024 at 12:02 PM Michael Ossipoff <email9648742 at gmail.com>
wrote:

> Of course I’m just guessing, but my guess is that “decapitation” is
> Closed’s new name for favorite-burial.
>
> Closed sometimes in invents new names without define them.
>
> IRV indeed shares Plurality’s need for favorite-burial defensive-strategy.
> I don’t like that, & wouldn’t propose IRV. There are a number of places
> where IRV is (the only electoral reform) up for enactment this year, In
> spite of that very  unlikeable strategy-need, I wanted to help campaign for
> its enactment, in the hope that the voters who’ve enacted it didn’t do so
> because they intend to bury their favorite, & so so won’t do so.
>
> But, because IRV is being fraudulently sold to them, with intentional
> lies, we can’t count on how people will vote when they find out about what
> they’ve enacted…when they find out about the lie.
>
> Therefore, regrettably, we shouldn’t support “RCV”.
>
>
> On Sun, Apr 28, 2024 at 11:15 Chris Benham <cbenhamau at yahoo.com.au> wrote:
>
>> Limelike,
>>
>> Can you please define and explain the "decapitation" strategy?   I
>> haven't heard of it.
>>
>> And can you elaborate a bit on this? :
>>
>> IRV is a good example of this. It's *usually* not susceptible to
>> strategy (in the IAC model), but I think of it as one of the most
>> strategy-afflicted methods on this list. It's vulnerable to some
>> particularly-egregious strategies (decapitation), ones that are complex or
>> difficult to explain (pushover), and many strategies [that?] don't have a
>> simple defensive counterstrategy available (like truncation).
>>
>>
>> Chris B.
>>
>> On 29/04/2024 2:31 am, Closed Limelike Curves wrote:
>>
>> Hi Kris, thanks for the results! They're definitely interesting.
>>
>> That said, I'm not sure how useful a metric raw probabilities provide; I
>> don't think they provide a very strong measure of how *severely* each
>> system is affected by strategy. Missing are:
>> 1. How much do voters have to distort their ballots? Is it just
>> truncation, compression (as with tied-at-the-top), or full decapitation?
>> 2. How hard is it to think of the strategy? Counterintuitive strategies
>> (e.g. randomized strategies or pushover) require large, organized parties
>> to educate their supporters about how to pull it off. This could be good or
>> bad depending on if you like institutionalized parties. Good: sometimes
>> people can't pull it off. Bad: this creates an incentive for strong parties
>> and partisanship. See the Alaska 2022 Senate race, where Democrats pulled
>> off a favorite-betrayal in support of Murkowski to avoid a center-squeeze.
>> 3. Is a counterstrategy available?
>> 4. How feasible is the strategy (does it involve many or few voters)?
>> 5. How bad would the effects of the strategy be? Borda is bad not just
>> because it's often susceptible to strategy, but because it gives turkeys a
>> solid chance of winning.
>>
>> IRV is a good example of this. It's *usually* not susceptible to
>> strategy (in the IAC model), but I think of it as one of the most
>> strategy-afflicted methods on this list. It's vulnerable to some
>> particularly-egregious strategies (decapitation), ones that are complex or
>> difficult to explain (pushover), and many strategies don't have a simple
>> defensive counterstrategy available (like truncation).
>>
>> A low-probability but occasionally high-impact strategy might be the
>> worst of both worlds; voters get lulled into a false sense of security by a
>> few elections where strategy doesn't matter, then suddenly find a candidate
>> they dislike elected because they failed to execute the appropriate
>> defensive strategy.
>>
>> ----
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>>
>>
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