MO
Michael Ossipoff
Mon, Apr 29, 2024 12:08 AM
Chris is right: Primarily it of course isn’t an honesty issue. No matter
how it’s presented, a method with IRV’s strategy problem should never be
proposed for public political elections.
…& that’s only the strategy problem, quite aside from its potential for
count-fraud, due to the elaborate count that it shares with other ranked
methods. …a problem made considerably worse if the count is automated, as
it would be here.
There’s no reason to propose something that bad when there are better
methods.
But I was willing to accept that serious favorite-burial need, &
count-fraud vulnerability, for no other reason than a hope that maybe most
voters wouldn’t favorite-bury (as I said in my previous reply).
But that depends on the voters knowing, accepting & liking what they’re
buying. Fraudulent sale? All bets are off.
On Sun, Apr 28, 2024 at 16:14 Chris Benham cbenhamau@yahoo.com.au wrote:
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
.
I don't like either term. For me, "burial" refers to something a voter
does to a candidate in the hope that will cause that candidate to lose to a
candidate the voter prefers, and not just to any insincere down-ranking.
So "favorite-burial" is an oxymoron that Mike O. likes to use.
"Favorite Betrayal" meaning to insincerely down-rank one's favourite, is
ok, but that could either be Compromise strategy (insincerely up-ranking X
to decrease the chance that X will lose to a candidate you like less) or
Push-over (insincerely up-ranking X to increase the chance that X will lose
to say F that you like better, instead of F losing to some Y that you like
less).
An attempt was made to standardise the terminology here quite a while ago:
http://condorcet.org/emr/defn.shtml
burying
Insincerely ranking an alternative lower in the hope of defeating it.
compromising
Insincerely ranking an alternative higher in the hope of getting it
elected.
push-over
The strategy of ranking a weak alternative higher than one's preferred
alternative, which may be useful in a method that violates monotonicity
https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#monotonicity
monotonicity
The property of a method where an alternative can never be made to succeed
by being ranked lower on some ballots. Doing this is using the "push-over
https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#push-over"
strategy.
The genius of STAR Voting is that it apparently technically doesn't
"violate monotonicity", but it is vastly more vulnerable to Push-over than
IRV which does, as I've explained previously.
I find the question of whether there have been mistakes or exaggerations
or false claims made by the IRV promoters to be completely irrelevant to,
and separate question from, whether its adoption in the US should be
supported.
Of more concern to me are the details of the ballot rules and
restrictions. I think it is more democratic for it to be relatively easy to
get on the ballot so as to allow the voters a wider choice of candidates. I
understand that typically voters are limited to 7 different "ranking
levels". Well say there are 9 candidates and my two least-preferred
candidates are the two front-runners and I have a preference between them.
If I vote sincerely my vote is just as wasted as if I had voted sincerely
in FPP.
IRV then doesn't have Clone Independence. One of the main points of
ranked-ballot versus FPP is to reduce the involuntarily wasted vote as much
as possible.
If such restrictive ballot rules are unavoidable, then I lose my
enthusiasm for IRV or Benham in favour of something with a truncation
incentive (and that is happy with equal-ranking if that isn't a problem for
the ballot rules) such as Smith//Approval (implicit).
Properly implemented Hare's Compromise incentive is practically nothing
by comparison with that of FPP, and no-one in Australia notices it. I
estimate it is also quite a bit weaker than that of STAR. Pushover
strategy in Hare is relatively difficult and risky in Hare and as far as I
know it's never been tried in Australia. Whereas STAR is a "festival of
Push-over" farce/nightmare.
And while (like STAR) it fails Condorcet, it has a solid set of
"representativeness" criterion compliances that together can be thought of
as weakened Condorcet and are worth quite a lot.
They are Dominant Coalition (a better stronger version of Mutual Majority
that so of course implies it) and Dominant Mutual Third and Condorcet
Loser. STAR only meets the last of those, the weakest.
Chris B.
On 29/04/2024 5:08 am, Closed Limelike Curves wrote:
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@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@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:
- How much do voters have to distort their ballots? Is it just
truncation, compression (as with tied-at-the-top), or full decapitation?
- 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.
- Is a counterstrategy available?
- How feasible is the strategy (does it involve many or few voters)?
- 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.
Election-Methods mailing list - see https://electorama.com/em for list info
Chris is right: Primarily it of course isn’t an honesty issue. No matter
how it’s presented, a method with IRV’s strategy problem should never be
proposed for public political elections.
…& that’s only the strategy problem, quite aside from its potential for
count-fraud, due to the elaborate count that it shares with other ranked
methods. …a problem made considerably worse if the count is automated, as
it would be here.
There’s no reason to propose something that bad when there are better
methods.
But I was willing to accept that serious favorite-burial need, &
count-fraud vulnerability, for no other reason than a hope that maybe most
voters wouldn’t favorite-bury (as I said in my previous reply).
But that depends on the voters knowing, accepting & liking what they’re
buying. Fraudulent sale? All bets are off.
On Sun, Apr 28, 2024 at 16:14 Chris Benham <cbenhamau@yahoo.com.au> wrote:
> 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>
> .
>
>
> I don't like either term. For me, "burial" refers to something a voter
> does to a candidate in the hope that will cause that candidate to lose to a
> candidate the voter prefers, and not just to any insincere down-ranking.
> So "favorite-burial" is an oxymoron that Mike O. likes to use.
>
> "Favorite Betrayal" meaning to insincerely down-rank one's favourite, is
> ok, but that could either be Compromise strategy (insincerely up-ranking X
> to decrease the chance that X will lose to a candidate you like less) or
> Push-over (insincerely up-ranking X to increase the chance that X will lose
> to say F that you like better, instead of F losing to some Y that you like
> less).
>
> An attempt was made to standardise the terminology here quite a while ago:
>
> http://condorcet.org/emr/defn.shtml
>
> *burying*
> Insincerely ranking an alternative lower in the hope of defeating it.
>
> *compromising*
> Insincerely ranking an alternative higher in the hope of getting it
> elected.
>
> *push-over*
> The strategy of ranking a weak alternative higher than one's preferred
> alternative, which may be useful in a method that violates monotonicity
> <https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#monotonicity>
>
> *monotonicity*
> The property of a method where an alternative can never be made to succeed
> by being ranked lower on some ballots. Doing this is using the "push-over
> <https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#push-over>"
> strategy.
>
>
>
> The genius of STAR Voting is that it apparently technically doesn't
> "violate monotonicity", but it is vastly more vulnerable to Push-over than
> IRV which does, as I've explained previously.
>
> I find the question of whether there have been mistakes or exaggerations
> or false claims made by the IRV promoters to be completely irrelevant to,
> and separate question from, whether its adoption in the US should be
> supported.
>
> Of more concern to me are the details of the ballot rules and
> restrictions. I think it is more democratic for it to be relatively easy to
> get on the ballot so as to allow the voters a wider choice of candidates. I
> understand that typically voters are limited to 7 different "ranking
> levels". Well say there are 9 candidates and my two least-preferred
> candidates are the two front-runners and I have a preference between them.
> If I vote sincerely my vote is just as wasted as if I had voted sincerely
> in FPP.
>
> IRV then doesn't have Clone Independence. One of the main points of
> ranked-ballot versus FPP is to reduce the involuntarily wasted vote as much
> as possible.
>
> If such restrictive ballot rules are unavoidable, then I lose my
> enthusiasm for IRV or Benham in favour of something with a truncation
> incentive (and that is happy with equal-ranking if that isn't a problem for
> the ballot rules) such as Smith//Approval (implicit).
>
> Properly implemented Hare's Compromise incentive is practically nothing
> by comparison with that of FPP, and no-one in Australia notices it. I
> estimate it is also quite a bit weaker than that of STAR. Pushover
> strategy in Hare is relatively difficult and risky in Hare and as far as I
> know it's never been tried in Australia. Whereas STAR is a "festival of
> Push-over" farce/nightmare.
>
> And while (like STAR) it fails Condorcet, it has a solid set of
> "representativeness" criterion compliances that together can be thought of
> as weakened Condorcet and are worth quite a lot.
>
> They are Dominant Coalition (a better stronger version of Mutual Majority
> that so of course implies it) and Dominant Mutual Third and Condorcet
> Loser. STAR only meets the last of those, the weakest.
>
> Chris B.
>
>
> On 29/04/2024 5:08 am, Closed Limelike Curves wrote:
>
> 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@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@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.
>>>
>>> ----
>>> Election-Methods mailing list - see https://electorama.com/em for list info
>>>
>>>
MO
Michael Ossipoff
Mon, Apr 29, 2024 12:15 AM
…&, as I likewise said, I wouldn’t have been willing to accept IRV’s
problems if it weren’t for the fact that it’s the only voting-system reform
that will be up for vote this year in several jurisdictions.
On Sun, Apr 28, 2024 at 17:08 Michael Ossipoff email9648742@gmail.com
wrote:
Chris is right: Primarily it of course isn’t an honesty issue. No matter
how it’s presented, a method with IRV’s strategy problem should never be
proposed for public political elections.
…& that’s only the strategy problem, quite aside from its potential for
count-fraud, due to the elaborate count that it shares with other ranked
methods. …a problem made considerably worse if the count is automated, as
it would be here.
There’s no reason to propose something that bad when there are better
methods.
But I was willing to accept that serious favorite-burial need, &
count-fraud vulnerability, for no other reason than a hope that maybe most
voters wouldn’t favorite-bury (as I said in my previous reply).
But that depends on the voters knowing, accepting & liking what they’re
buying. Fraudulent sale? All bets are off.
On Sun, Apr 28, 2024 at 16:14 Chris Benham cbenhamau@yahoo.com.au wrote:
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
.
I don't like either term. For me, "burial" refers to something a voter
does to a candidate in the hope that will cause that candidate to lose to a
candidate the voter prefers, and not just to any insincere down-ranking.
So "favorite-burial" is an oxymoron that Mike O. likes to use.
"Favorite Betrayal" meaning to insincerely down-rank one's favourite, is
ok, but that could either be Compromise strategy (insincerely up-ranking X
to decrease the chance that X will lose to a candidate you like less) or
Push-over (insincerely up-ranking X to increase the chance that X will lose
to say F that you like better, instead of F losing to some Y that you like
less).
An attempt was made to standardise the terminology here quite a while ago:
http://condorcet.org/emr/defn.shtml
burying
Insincerely ranking an alternative lower in the hope of defeating it.
compromising
Insincerely ranking an alternative higher in the hope of getting it
elected.
push-over
The strategy of ranking a weak alternative higher than one's preferred
alternative, which may be useful in a method that violates monotonicity
https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#monotonicity
monotonicity
The property of a method where an alternative can never be made to
succeed by being ranked lower on some ballots. Doing this is using the "
push-over
https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#push-over"
strategy.
The genius of STAR Voting is that it apparently technically doesn't
"violate monotonicity", but it is vastly more vulnerable to Push-over than
IRV which does, as I've explained previously.
I find the question of whether there have been mistakes or exaggerations
or false claims made by the IRV promoters to be completely irrelevant to,
and separate question from, whether its adoption in the US should be
supported.
Of more concern to me are the details of the ballot rules and
restrictions. I think it is more democratic for it to be relatively easy to
get on the ballot so as to allow the voters a wider choice of candidates. I
understand that typically voters are limited to 7 different "ranking
levels". Well say there are 9 candidates and my two least-preferred
candidates are the two front-runners and I have a preference between them.
If I vote sincerely my vote is just as wasted as if I had voted sincerely
in FPP.
IRV then doesn't have Clone Independence. One of the main points of
ranked-ballot versus FPP is to reduce the involuntarily wasted vote as much
as possible.
If such restrictive ballot rules are unavoidable, then I lose my
enthusiasm for IRV or Benham in favour of something with a truncation
incentive (and that is happy with equal-ranking if that isn't a problem for
the ballot rules) such as Smith//Approval (implicit).
Properly implemented Hare's Compromise incentive is practically nothing
by comparison with that of FPP, and no-one in Australia notices it. I
estimate it is also quite a bit weaker than that of STAR. Pushover
strategy in Hare is relatively difficult and risky in Hare and as far as I
know it's never been tried in Australia. Whereas STAR is a "festival of
Push-over" farce/nightmare.
And while (like STAR) it fails Condorcet, it has a solid set of
"representativeness" criterion compliances that together can be thought of
as weakened Condorcet and are worth quite a lot.
They are Dominant Coalition (a better stronger version of Mutual Majority
that so of course implies it) and Dominant Mutual Third and Condorcet
Loser. STAR only meets the last of those, the weakest.
Chris B.
On 29/04/2024 5:08 am, Closed Limelike Curves wrote:
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@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@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:
- How much do voters have to distort their ballots? Is it just
truncation, compression (as with tied-at-the-top), or full decapitation?
- 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.
- Is a counterstrategy available?
- How feasible is the strategy (does it involve many or few voters)?
- 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.
Election-Methods mailing list - see https://electorama.com/em for list info
…&, as I likewise said, I wouldn’t have been willing to accept IRV’s
problems if it weren’t for the fact that it’s the only voting-system reform
that will be up for vote this year in several jurisdictions.
On Sun, Apr 28, 2024 at 17:08 Michael Ossipoff <email9648742@gmail.com>
wrote:
> Chris is right: Primarily it of course isn’t an honesty issue. No matter
> how it’s presented, a method with IRV’s strategy problem should never be
> proposed for public political elections.
>
> …& that’s only the strategy problem, quite aside from its potential for
> count-fraud, due to the elaborate count that it shares with other ranked
> methods. …a problem made considerably worse if the count is automated, as
> it would be here.
>
> There’s no reason to propose something that bad when there are better
> methods.
>
> But I was willing to accept that serious favorite-burial need, &
> count-fraud vulnerability, for no other reason than a hope that maybe most
> voters wouldn’t favorite-bury (as I said in my previous reply).
>
> But that depends on the voters knowing, accepting & liking what they’re
> buying. Fraudulent sale? All bets are off.
>
> On Sun, Apr 28, 2024 at 16:14 Chris Benham <cbenhamau@yahoo.com.au> wrote:
>
>> 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>
>> .
>>
>>
>> I don't like either term. For me, "burial" refers to something a voter
>> does to a candidate in the hope that will cause that candidate to lose to a
>> candidate the voter prefers, and not just to any insincere down-ranking.
>> So "favorite-burial" is an oxymoron that Mike O. likes to use.
>>
>> "Favorite Betrayal" meaning to insincerely down-rank one's favourite, is
>> ok, but that could either be Compromise strategy (insincerely up-ranking X
>> to decrease the chance that X will lose to a candidate you like less) or
>> Push-over (insincerely up-ranking X to increase the chance that X will lose
>> to say F that you like better, instead of F losing to some Y that you like
>> less).
>>
>> An attempt was made to standardise the terminology here quite a while ago:
>>
>> http://condorcet.org/emr/defn.shtml
>>
>> *burying*
>> Insincerely ranking an alternative lower in the hope of defeating it.
>>
>> *compromising*
>> Insincerely ranking an alternative higher in the hope of getting it
>> elected.
>>
>> *push-over*
>> The strategy of ranking a weak alternative higher than one's preferred
>> alternative, which may be useful in a method that violates monotonicity
>> <https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#monotonicity>
>>
>> *monotonicity*
>> The property of a method where an alternative can never be made to
>> succeed by being ranked lower on some ballots. Doing this is using the "
>> push-over
>> <https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#push-over>"
>> strategy.
>>
>>
>>
>> The genius of STAR Voting is that it apparently technically doesn't
>> "violate monotonicity", but it is vastly more vulnerable to Push-over than
>> IRV which does, as I've explained previously.
>>
>> I find the question of whether there have been mistakes or exaggerations
>> or false claims made by the IRV promoters to be completely irrelevant to,
>> and separate question from, whether its adoption in the US should be
>> supported.
>>
>> Of more concern to me are the details of the ballot rules and
>> restrictions. I think it is more democratic for it to be relatively easy to
>> get on the ballot so as to allow the voters a wider choice of candidates. I
>> understand that typically voters are limited to 7 different "ranking
>> levels". Well say there are 9 candidates and my two least-preferred
>> candidates are the two front-runners and I have a preference between them.
>> If I vote sincerely my vote is just as wasted as if I had voted sincerely
>> in FPP.
>>
>> IRV then doesn't have Clone Independence. One of the main points of
>> ranked-ballot versus FPP is to reduce the involuntarily wasted vote as much
>> as possible.
>>
>> If such restrictive ballot rules are unavoidable, then I lose my
>> enthusiasm for IRV or Benham in favour of something with a truncation
>> incentive (and that is happy with equal-ranking if that isn't a problem for
>> the ballot rules) such as Smith//Approval (implicit).
>>
>> Properly implemented Hare's Compromise incentive is practically nothing
>> by comparison with that of FPP, and no-one in Australia notices it. I
>> estimate it is also quite a bit weaker than that of STAR. Pushover
>> strategy in Hare is relatively difficult and risky in Hare and as far as I
>> know it's never been tried in Australia. Whereas STAR is a "festival of
>> Push-over" farce/nightmare.
>>
>> And while (like STAR) it fails Condorcet, it has a solid set of
>> "representativeness" criterion compliances that together can be thought of
>> as weakened Condorcet and are worth quite a lot.
>>
>> They are Dominant Coalition (a better stronger version of Mutual Majority
>> that so of course implies it) and Dominant Mutual Third and Condorcet
>> Loser. STAR only meets the last of those, the weakest.
>>
>> Chris B.
>>
>>
>> On 29/04/2024 5:08 am, Closed Limelike Curves wrote:
>>
>> 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@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@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.
>>>>
>>>> ----
>>>> Election-Methods mailing list - see https://electorama.com/em for list info
>>>>
>>>>
CL
Closed Limelike Curves
Mon, Apr 29, 2024 2:51 AM
Chris—here in the United States, pushover is well-known and frequently
used, in the context of partisan primaries. We call it "raiding".
Usually it's hard to notice. I suspect the same is true in Australia. The
only difference is here in the United States we manage to notice it from
time to time, because what happens is candidates will run big advertisement
operations that aim to promote an extreme candidate in a primary and give
an easy win. I can't prove the same thing happens with voters, but I'm not
sure how you *would *prove that.
I suspect Australia doesn't have any examples of turkey-raising because it
only has two major parties in its IRV seats, at which point the strategy is
pointless.
On Sun, Apr 28, 2024 at 4:14 PM Chris Benham cbenhamau@yahoo.com.au wrote:
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
.
I don't like either term. For me, "burial" refers to something a voter
does to a candidate in the hope that will cause that candidate to lose to a
candidate the voter prefers, and not just to any insincere down-ranking.
So "favorite-burial" is an oxymoron that Mike O. likes to use.
"Favorite Betrayal" meaning to insincerely down-rank one's favourite, is
ok, but that could either be Compromise strategy (insincerely up-ranking X
to decrease the chance that X will lose to a candidate you like less) or
Push-over (insincerely up-ranking X to increase the chance that X will lose
to say F that you like better, instead of F losing to some Y that you like
less).
An attempt was made to standardise the terminology here quite a while ago:
http://condorcet.org/emr/defn.shtml
burying
Insincerely ranking an alternative lower in the hope of defeating it.
compromising
Insincerely ranking an alternative higher in the hope of getting it
elected.
push-over
The strategy of ranking a weak alternative higher than one's preferred
alternative, which may be useful in a method that violates monotonicity
https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#monotonicity
monotonicity
The property of a method where an alternative can never be made to succeed
by being ranked lower on some ballots. Doing this is using the "push-over
https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#push-over"
strategy.
The genius of STAR Voting is that it apparently technically doesn't
"violate monotonicity", but it is vastly more vulnerable to Push-over than
IRV which does, as I've explained previously.
I find the question of whether there have been mistakes or exaggerations
or false claims made by the IRV promoters to be completely irrelevant to,
and separate question from, whether its adoption in the US should be
supported.
Of more concern to me are the details of the ballot rules and
restrictions. I think it is more democratic for it to be relatively easy to
get on the ballot so as to allow the voters a wider choice of candidates. I
understand that typically voters are limited to 7 different "ranking
levels". Well say there are 9 candidates and my two least-preferred
candidates are the two front-runners and I have a preference between them.
If I vote sincerely my vote is just as wasted as if I had voted sincerely
in FPP.
IRV then doesn't have Clone Independence. One of the main points of
ranked-ballot versus FPP is to reduce the involuntarily wasted vote as much
as possible.
If such restrictive ballot rules are unavoidable, then I lose my
enthusiasm for IRV or Benham in favour of something with a truncation
incentive (and that is happy with equal-ranking if that isn't a problem for
the ballot rules) such as Smith//Approval (implicit).
Properly implemented Hare's Compromise incentive is practically nothing
by comparison with that of FPP, and no-one in Australia notices it. I
estimate it is also quite a bit weaker than that of STAR. Pushover
strategy in Hare is relatively difficult and risky in Hare and as far as I
know it's never been tried in Australia. Whereas STAR is a "festival of
Push-over" farce/nightmare.
And while (like STAR) it fails Condorcet, it has a solid set of
"representativeness" criterion compliances that together can be thought of
as weakened Condorcet and are worth quite a lot.
They are Dominant Coalition (a better stronger version of Mutual Majority
that so of course implies it) and Dominant Mutual Third and Condorcet
Loser. STAR only meets the last of those, the weakest.
Chris B.
On 29/04/2024 5:08 am, Closed Limelike Curves wrote:
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@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@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:
- How much do voters have to distort their ballots? Is it just
truncation, compression (as with tied-at-the-top), or full decapitation?
- 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.
- Is a counterstrategy available?
- How feasible is the strategy (does it involve many or few voters)?
- 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.
Election-Methods mailing list - see https://electorama.com/em for list info
Chris—here in the United States, pushover is well-known and frequently
used, in the context of partisan primaries. We call it "raiding".
Usually it's hard to notice. I suspect the same is true in Australia. The
only difference is here in the United States we manage to notice it from
time to time, because what happens is candidates will run big advertisement
operations that aim to promote an extreme candidate in a primary and give
an easy win. I can't prove the same thing happens with voters, but I'm not
sure how you *would *prove that.
I suspect Australia doesn't have any examples of turkey-raising because it
only has two major parties in its IRV seats, at which point the strategy is
pointless.
On Sun, Apr 28, 2024 at 4:14 PM Chris Benham <cbenhamau@yahoo.com.au> wrote:
> 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>
> .
>
>
> I don't like either term. For me, "burial" refers to something a voter
> does to a candidate in the hope that will cause that candidate to lose to a
> candidate the voter prefers, and not just to any insincere down-ranking.
> So "favorite-burial" is an oxymoron that Mike O. likes to use.
>
> "Favorite Betrayal" meaning to insincerely down-rank one's favourite, is
> ok, but that could either be Compromise strategy (insincerely up-ranking X
> to decrease the chance that X will lose to a candidate you like less) or
> Push-over (insincerely up-ranking X to increase the chance that X will lose
> to say F that you like better, instead of F losing to some Y that you like
> less).
>
> An attempt was made to standardise the terminology here quite a while ago:
>
> http://condorcet.org/emr/defn.shtml
>
> *burying*
> Insincerely ranking an alternative lower in the hope of defeating it.
>
> *compromising*
> Insincerely ranking an alternative higher in the hope of getting it
> elected.
>
> *push-over*
> The strategy of ranking a weak alternative higher than one's preferred
> alternative, which may be useful in a method that violates monotonicity
> <https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#monotonicity>
>
> *monotonicity*
> The property of a method where an alternative can never be made to succeed
> by being ranked lower on some ballots. Doing this is using the "push-over
> <https://web.archive.org/web/20090613041320/http://condorcet.org/emr/defn.shtml#push-over>"
> strategy.
>
>
>
> The genius of STAR Voting is that it apparently technically doesn't
> "violate monotonicity", but it is vastly more vulnerable to Push-over than
> IRV which does, as I've explained previously.
>
> I find the question of whether there have been mistakes or exaggerations
> or false claims made by the IRV promoters to be completely irrelevant to,
> and separate question from, whether its adoption in the US should be
> supported.
>
> Of more concern to me are the details of the ballot rules and
> restrictions. I think it is more democratic for it to be relatively easy to
> get on the ballot so as to allow the voters a wider choice of candidates. I
> understand that typically voters are limited to 7 different "ranking
> levels". Well say there are 9 candidates and my two least-preferred
> candidates are the two front-runners and I have a preference between them.
> If I vote sincerely my vote is just as wasted as if I had voted sincerely
> in FPP.
>
> IRV then doesn't have Clone Independence. One of the main points of
> ranked-ballot versus FPP is to reduce the involuntarily wasted vote as much
> as possible.
>
> If such restrictive ballot rules are unavoidable, then I lose my
> enthusiasm for IRV or Benham in favour of something with a truncation
> incentive (and that is happy with equal-ranking if that isn't a problem for
> the ballot rules) such as Smith//Approval (implicit).
>
> Properly implemented Hare's Compromise incentive is practically nothing
> by comparison with that of FPP, and no-one in Australia notices it. I
> estimate it is also quite a bit weaker than that of STAR. Pushover
> strategy in Hare is relatively difficult and risky in Hare and as far as I
> know it's never been tried in Australia. Whereas STAR is a "festival of
> Push-over" farce/nightmare.
>
> And while (like STAR) it fails Condorcet, it has a solid set of
> "representativeness" criterion compliances that together can be thought of
> as weakened Condorcet and are worth quite a lot.
>
> They are Dominant Coalition (a better stronger version of Mutual Majority
> that so of course implies it) and Dominant Mutual Third and Condorcet
> Loser. STAR only meets the last of those, the weakest.
>
> Chris B.
>
>
> On 29/04/2024 5:08 am, Closed Limelike Curves wrote:
>
> 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@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@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.
>>>
>>> ----
>>> Election-Methods mailing list - see https://electorama.com/em for list info
>>>
>>>
MO
Michael Ossipoff
Mon, Apr 29, 2024 7:36 PM
When you do that simulation, I hope that you’ll repeat each simulated
election, but with the largest losing-faction burying the CW.
…recording & reporting, for each Condorcet-complying method, the ratio of
burial’s successes to burial’s backfires (in which it elects someone whom
the buriers like less than the CW).
On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm km_elmet@t-online.de
wrote:
On 2024-04-27 14:10, Chris Benham wrote:
Kristofer,
How did Approval interpret these fully ranked ballots?
That's part of why I'm just referring to JGA. To do the simulation
myself, I would have to implicitly code a guideline that says where the
cutoff should be placed, given candidate-voter distances (which stand in
for absolute utilities). (The other part is that my simulator doesn't
support forcing the strategic ballots to be approval-style either yet.)
Unfortunately, James doesn't say just how he did it, so I'm CCing this
post to him. How were the approval ballots generated in "Four
Condorcet-Hare hybrid methods"?
In the absence of any information, I'd guess he used above-mean utility
thresholding. The strategic ballots (used to try to flip the winner)
don't have to care about utility at all: that process just tries
approval ballots at random until something works.
-km
Election-Methods mailing list - see https://electorama.com/em for list
info
When you do that simulation, I hope that you’ll repeat each simulated
election, but with the largest losing-faction burying the CW.
…recording & reporting, for each Condorcet-complying method, the ratio of
burial’s successes to burial’s backfires (in which it elects someone whom
the buriers like less than the CW).
On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm <km_elmet@t-online.de>
wrote:
> On 2024-04-27 14:10, Chris Benham wrote:
> > Kristofer,
> >
> > How did Approval interpret these fully ranked ballots?
>
> That's part of why I'm just referring to JGA. To do the simulation
> myself, I would have to implicitly code a guideline that says where the
> cutoff should be placed, given candidate-voter distances (which stand in
> for absolute utilities). (The other part is that my simulator doesn't
> support forcing the strategic ballots to be approval-style either yet.)
>
> Unfortunately, James doesn't say just how he did it, so I'm CCing this
> post to him. How were the approval ballots generated in "Four
> Condorcet-Hare hybrid methods"?
>
> In the absence of any information, I'd guess he used above-mean utility
> thresholding. The strategic ballots (used to try to flip the winner)
> don't have to care about utility at all: that process just tries
> approval ballots at random until something works.
>
> -km
> ----
> Election-Methods mailing list - see https://electorama.com/em for list
> info
>
CL
Closed Limelike Curves
Tue, Apr 30, 2024 1:20 AM
I generally use the stochastic rounding model, i.e. I treat approval as
just being score voting. Mostly because, if I don't:
- Why stop at 2 categories instead of a full analysis depending on whether
I use 2, 3, 4, ...?
- I can make approval satisfy increasingly ridiculous sets of properties
by using otherwise-equivalent definitions of criteria. (Did you guys know
approval is a Condorcet method? It's true! If, in every pairwise matchup, a
candidate is given a strictly higher score than their opponent by most
voters, that candidate wins under approval!)
On Mon, Apr 29, 2024 at 12:37 PM Michael Ossipoff email9648742@gmail.com
wrote:
When you do that simulation, I hope that you’ll repeat each simulated
election, but with the largest losing-faction burying the CW.
…recording & reporting, for each Condorcet-complying method, the ratio of
burial’s successes to burial’s backfires (in which it elects someone whom
the buriers like less than the CW).
On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm km_elmet@t-online.de
wrote:
On 2024-04-27 14:10, Chris Benham wrote:
Kristofer,
How did Approval interpret these fully ranked ballots?
That's part of why I'm just referring to JGA. To do the simulation
myself, I would have to implicitly code a guideline that says where the
cutoff should be placed, given candidate-voter distances (which stand in
for absolute utilities). (The other part is that my simulator doesn't
support forcing the strategic ballots to be approval-style either yet.)
Unfortunately, James doesn't say just how he did it, so I'm CCing this
post to him. How were the approval ballots generated in "Four
Condorcet-Hare hybrid methods"?
In the absence of any information, I'd guess he used above-mean utility
thresholding. The strategic ballots (used to try to flip the winner)
don't have to care about utility at all: that process just tries
approval ballots at random until something works.
-km
Election-Methods mailing list - see https://electorama.com/em for list
info
I generally use the stochastic rounding model, i.e. I treat approval as
just being score voting. Mostly because, if I don't:
1) Why stop at 2 categories instead of a full analysis depending on whether
I use 2, 3, 4, ...?
2) I can make approval satisfy increasingly ridiculous sets of properties
by using otherwise-equivalent definitions of criteria. (Did you guys know
approval is a Condorcet method? It's true! If, in every pairwise matchup, a
candidate is given a strictly higher score than their opponent by most
voters, that candidate wins under approval!)
On Mon, Apr 29, 2024 at 12:37 PM Michael Ossipoff <email9648742@gmail.com>
wrote:
> When you do that simulation, I hope that you’ll repeat each simulated
> election, but with the largest losing-faction burying the CW.
>
> …recording & reporting, for each Condorcet-complying method, the ratio of
> burial’s successes to burial’s backfires (in which it elects someone whom
> the buriers like less than the CW).
>
>
> On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm <km_elmet@t-online.de>
> wrote:
>
>> On 2024-04-27 14:10, Chris Benham wrote:
>> > Kristofer,
>> >
>> > How did Approval interpret these fully ranked ballots?
>>
>> That's part of why I'm just referring to JGA. To do the simulation
>> myself, I would have to implicitly code a guideline that says where the
>> cutoff should be placed, given candidate-voter distances (which stand in
>> for absolute utilities). (The other part is that my simulator doesn't
>> support forcing the strategic ballots to be approval-style either yet.)
>>
>> Unfortunately, James doesn't say just how he did it, so I'm CCing this
>> post to him. How were the approval ballots generated in "Four
>> Condorcet-Hare hybrid methods"?
>>
>> In the absence of any information, I'd guess he used above-mean utility
>> thresholding. The strategic ballots (used to try to flip the winner)
>> don't have to care about utility at all: that process just tries
>> approval ballots at random until something works.
>>
>> -km
>> ----
>> Election-Methods mailing list - see https://electorama.com/em for list
>> info
>>
> ----
> Election-Methods mailing list - see https://electorama.com/em for list
> info
>
CB
Chris Benham
Tue, Apr 30, 2024 2:56 AM
I think it is quite a bit more egregious if the Condorcet faction can be
successfully buried by a smaller faction, especially if the Condorcet
faction is the largest.
So simulation information that casts light on how methods vary on that
score would be interesting.
Chris B.
On 30/04/2024 5:06 am, Michael Ossipoff wrote:
When you do that simulation, I hope that you’ll repeat each simulated
election, but with the largest losing-faction burying the CW.
…recording & reporting, for each Condorcet-complying method, the ratio
of burial’s successes to burial’s backfires (in which it elects
someone whom the buriers like less than the CW).
On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm
km_elmet@t-online.de wrote:
On 2024-04-27 14:10, Chris Benham wrote:
Kristofer,
How did Approval interpret these fully ranked ballots?
That's part of why I'm just referring to JGA. To do the simulation
myself, I would have to implicitly code a guideline that says
where the
cutoff should be placed, given candidate-voter distances (which
stand in
for absolute utilities). (The other part is that my simulator doesn't
support forcing the strategic ballots to be approval-style either
yet.)
Unfortunately, James doesn't say just how he did it, so I'm CCing
this
post to him. How were the approval ballots generated in "Four
Condorcet-Hare hybrid methods"?
In the absence of any information, I'd guess he used above-mean
utility
thresholding. The strategic ballots (used to try to flip the winner)
don't have to care about utility at all: that process just tries
approval ballots at random until something works.
-km
----
Election-Methods mailing list - see https://electorama.com/em for
list info
I think it is quite a bit more egregious if the Condorcet faction can be
successfully buried by a smaller faction, especially if the Condorcet
faction is the largest.
So simulation information that casts light on how methods vary on that
score would be interesting.
Chris B.
On 30/04/2024 5:06 am, Michael Ossipoff wrote:
> When you do that simulation, I hope that you’ll repeat each simulated
> election, but with the largest losing-faction burying the CW.
>
> …recording & reporting, for each Condorcet-complying method, the ratio
> of burial’s successes to burial’s backfires (in which it elects
> someone whom the buriers like less than the CW).
>
>
> On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm
> <km_elmet@t-online.de> wrote:
>
> On 2024-04-27 14:10, Chris Benham wrote:
> > Kristofer,
> >
> > How did Approval interpret these fully ranked ballots?
>
> That's part of why I'm just referring to JGA. To do the simulation
> myself, I would have to implicitly code a guideline that says
> where the
> cutoff should be placed, given candidate-voter distances (which
> stand in
> for absolute utilities). (The other part is that my simulator doesn't
> support forcing the strategic ballots to be approval-style either
> yet.)
>
> Unfortunately, James doesn't say just how he did it, so I'm CCing
> this
> post to him. How were the approval ballots generated in "Four
> Condorcet-Hare hybrid methods"?
>
> In the absence of any information, I'd guess he used above-mean
> utility
> thresholding. The strategic ballots (used to try to flip the winner)
> don't have to care about utility at all: that process just tries
> approval ballots at random until something works.
>
> -km
> ----
> Election-Methods mailing list - see https://electorama.com/em for
> list info
>
MO
Michael Ossipoff
Tue, Apr 30, 2024 5:21 AM
True. Though if the biggest can’t succeed that means it’s a good method, if
the smallest can succeed that means it’s a bad method.
So maybe best to check for both.
On Mon, Apr 29, 2024 at 19:56 Chris Benham cbenhamau@yahoo.com.au wrote:
I think it is quite a bit more egregious if the Condorcet faction can be
successfully buried by a smaller faction, especially if the Condorcet
faction is the largest.
So simulation information that casts light on how methods vary on that
score would be interesting.
Chris B.
On 30/04/2024 5:06 am, Michael Ossipoff wrote:
When you do that simulation, I hope that you’ll repeat each simulated
election, but with the largest losing-faction burying the CW.
…recording & reporting, for each Condorcet-complying method, the ratio of
burial’s successes to burial’s backfires (in which it elects someone whom
the buriers like less than the CW).
On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm km_elmet@t-online.de
wrote:
On 2024-04-27 14:10, Chris Benham wrote:
Kristofer,
How did Approval interpret these fully ranked ballots?
That's part of why I'm just referring to JGA. To do the simulation
myself, I would have to implicitly code a guideline that says where the
cutoff should be placed, given candidate-voter distances (which stand in
for absolute utilities). (The other part is that my simulator doesn't
support forcing the strategic ballots to be approval-style either yet.)
Unfortunately, James doesn't say just how he did it, so I'm CCing this
post to him. How were the approval ballots generated in "Four
Condorcet-Hare hybrid methods"?
In the absence of any information, I'd guess he used above-mean utility
thresholding. The strategic ballots (used to try to flip the winner)
don't have to care about utility at all: that process just tries
approval ballots at random until something works.
-km
Election-Methods mailing list - see https://electorama.com/em for list
info
True. Though if the biggest can’t succeed that means it’s a good method, if
the smallest *can* succeed that means it’s a bad method.
So maybe best to check for both.
On Mon, Apr 29, 2024 at 19:56 Chris Benham <cbenhamau@yahoo.com.au> wrote:
> I think it is quite a bit more egregious if the Condorcet faction can be
> successfully buried by a smaller faction, especially if the Condorcet
> faction is the largest.
>
> So simulation information that casts light on how methods vary on that
> score would be interesting.
>
> Chris B.
>
> On 30/04/2024 5:06 am, Michael Ossipoff wrote:
>
> When you do that simulation, I hope that you’ll repeat each simulated
> election, but with the largest losing-faction burying the CW.
>
> …recording & reporting, for each Condorcet-complying method, the ratio of
> burial’s successes to burial’s backfires (in which it elects someone whom
> the buriers like less than the CW).
>
>
> On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm <km_elmet@t-online.de>
> wrote:
>
>> On 2024-04-27 14:10, Chris Benham wrote:
>> > Kristofer,
>> >
>> > How did Approval interpret these fully ranked ballots?
>>
>> That's part of why I'm just referring to JGA. To do the simulation
>> myself, I would have to implicitly code a guideline that says where the
>> cutoff should be placed, given candidate-voter distances (which stand in
>> for absolute utilities). (The other part is that my simulator doesn't
>> support forcing the strategic ballots to be approval-style either yet.)
>>
>> Unfortunately, James doesn't say just how he did it, so I'm CCing this
>> post to him. How were the approval ballots generated in "Four
>> Condorcet-Hare hybrid methods"?
>>
>> In the absence of any information, I'd guess he used above-mean utility
>> thresholding. The strategic ballots (used to try to flip the winner)
>> don't have to care about utility at all: that process just tries
>> approval ballots at random until something works.
>>
>> -km
>> ----
>> Election-Methods mailing list - see https://electorama.com/em for list
>> info
>>
>
MO
Michael Ossipoff
Tue, Apr 30, 2024 5:24 AM
So simulation information that casts light on how methods vary on that
score would be interesting.
Absolutely. …& important to find-out. …about all familiar proposed
Condorcet-complying methods.
Chris B.
On 30/04/2024 5:06 am, Michael Ossipoff wrote:
When you do that simulation, I hope that you’ll repeat each simulated
election, but with the largest losing-faction burying the CW.
…recording & reporting, for each Condorcet-complying method, the ratio of
burial’s successes to burial’s backfires (in which it elects someone whom
the buriers like less than the CW).
On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm km_elmet@t-online.de
wrote:
On 2024-04-27 14:10, Chris Benham wrote:
Kristofer,
How did Approval interpret these fully ranked ballots?
That's part of why I'm just referring to JGA. To do the simulation
myself, I would have to implicitly code a guideline that says where the
cutoff should be placed, given candidate-voter distances (which stand in
for absolute utilities). (The other part is that my simulator doesn't
support forcing the strategic ballots to be approval-style either yet.)
Unfortunately, James doesn't say just how he did it, so I'm CCing this
post to him. How were the approval ballots generated in "Four
Condorcet-Hare hybrid methods"?
In the absence of any information, I'd guess he used above-mean utility
thresholding. The strategic ballots (used to try to flip the winner)
don't have to care about utility at all: that process just tries
approval ballots at random until something works.
-km
Election-Methods mailing list - see https://electorama.com/em for list
info
On Mon, Apr 29, 2024 at 19:56 Chris Benham <cbenhamau@yahoo.com.au> wrote:
> So simulation information that casts light on how methods vary on that
> score would be interesting.
>
Absolutely. …& important to find-out. …about all familiar proposed
Condorcet-complying methods.
>
>
> Chris B.
>
> On 30/04/2024 5:06 am, Michael Ossipoff wrote:
>
> When you do that simulation, I hope that you’ll repeat each simulated
> election, but with the largest losing-faction burying the CW.
>
> …recording & reporting, for each Condorcet-complying method, the ratio of
> burial’s successes to burial’s backfires (in which it elects someone whom
> the buriers like less than the CW).
>
>
> On Sat, Apr 27, 2024 at 05:48 Kristofer Munsterhjelm <km_elmet@t-online.de>
> wrote:
>
>> On 2024-04-27 14:10, Chris Benham wrote:
>> > Kristofer,
>> >
>> > How did Approval interpret these fully ranked ballots?
>>
>> That's part of why I'm just referring to JGA. To do the simulation
>> myself, I would have to implicitly code a guideline that says where the
>> cutoff should be placed, given candidate-voter distances (which stand in
>> for absolute utilities). (The other part is that my simulator doesn't
>> support forcing the strategic ballots to be approval-style either yet.)
>>
>> Unfortunately, James doesn't say just how he did it, so I'm CCing this
>> post to him. How were the approval ballots generated in "Four
>> Condorcet-Hare hybrid methods"?
>>
>> In the absence of any information, I'd guess he used above-mean utility
>> thresholding. The strategic ballots (used to try to flip the winner)
>> don't have to care about utility at all: that process just tries
>> approval ballots at random until something works.
>>
>> -km
>> ----
>> Election-Methods mailing list - see https://electorama.com/em for list
>> info
>>
>
MO
Michael Ossipoff
Fri, May 3, 2024 9:18 PM
Then Plurality is better than Black & Score; & Benham & Woodall are no
better than IRV; & IRV is 4 times better than the best Condorcet methods?
Of course JGA’s results lead to similar questions.
Doesn’t this bring into question the meaningfulness & usefulness of
manipulability as a measure of merit?
IRV has an incomparably worse strategy problem than the best Condorcet
methods.
Plurality is incomparably strategically worse than Approval.
Benham & Woodall, as everyone would agree, significantly improve on IRV.
On Sat, Apr 27, 2024 at 04:38 Kristofer Munsterhjelm km_elmet@t-online.de
wrote:
Here are voter manipulability stats for some of the poll methods, using
James Green-Armytage's spatial model with 4 dimensions, 4 candidates and
99 voters. Each method is tested on 500k elections, with 32k attempts to
strategize per election.
The manipulability value is the fraction of elections in this model
where the method elected a unique winner, and voters who preferred
somebody else to the current winner could get that somebody elected by
changing their ballots. Note that it does not check strategic nomination.
I've prefixed entries that aren't actually part of the poll with an
asterisk. I'll explain later why I've included them. Entries prefixed
with a number sign are from JGA as my simulator doesn't support them.[1]
The simulator uses full ballots, so Smith//DAC is the same as
Smith//DSC. If truncation would make the method more resistant, that's
not reflected here.
0.698 *Borda
0.668 #Approval (from JGA)
0.545 Condorcet//Borda (Black)
0.480 Copeland//Borda (Ranked Robin)
0.417 Plurality
0.417 Smith//DAC
0.412 *BTR-IRV
0.350 Baldwin
0.333 Raynaud (Gross Loser Elimination)
0.333 Schulze(wv)
0.332 Minmax(wv)
0.321 Ranked Pairs(wv)
0.075 Woodall, Schwartz-Woodall
0.074 RCIPE
0.074 IRV
0.074 Benham
I've included Borda to show that my results are similar to James Green
Armytage's. (Compare also the results minmax results.) In addition, I've
included BTR-IRV to see how well it would do. Too bad it didn't do
better, though...
My simulator show higher manipulability for IRV and the Condorcet-IRV
hybrids than JGA's simulator did. I think this comes down to that my
simulator is more thorough and thus is able to uncover more
nonmonotonicity- and pushover-related strategies.
Finally, I'm working on the cardinal methods, but the devil's in the
details so it's taking a lot longer than expected. More about that when
I've solved it. But my preliminary tests put Smith-Range around 0.5 and
STAR as worse than this. Unnormalized (fixed scale) Range, though not a
poll method, even does worse than Borda. And if the preliminary tests
give some indication, all the Range/Score-based methods do worse than
Plurality.
-km
[1] Green-Armytage, James (2011). "Four Condorcet-Hare hybrid methods
for single-winner elections". Voting matters (29): p. 7;
https://www.votingmatters.org.uk/ISSUE29/I29P1.pdf
Election-Methods mailing list - see https://electorama.com/em for list
info
Then Plurality is better than Black & Score; & Benham & Woodall are no
better than IRV; & IRV is 4 times better than the best Condorcet methods?
Of course JGA’s results lead to similar questions.
Doesn’t this bring into question the meaningfulness & usefulness of
manipulability as a measure of merit?
IRV has an incomparably worse strategy problem than the best Condorcet
methods.
Plurality is incomparably strategically worse than Approval.
Benham & Woodall, as everyone would agree, significantly improve on IRV.
On Sat, Apr 27, 2024 at 04:38 Kristofer Munsterhjelm <km_elmet@t-online.de>
wrote:
> Here are voter manipulability stats for some of the poll methods, using
> James Green-Armytage's spatial model with 4 dimensions, 4 candidates and
> 99 voters. Each method is tested on 500k elections, with 32k attempts to
> strategize per election.
>
> The manipulability value is the fraction of elections in this model
> where the method elected a unique winner, and voters who preferred
> somebody else to the current winner could get that somebody elected by
> changing their ballots. Note that it does *not* check strategic nomination.
>
> I've prefixed entries that aren't actually part of the poll with an
> asterisk. I'll explain later why I've included them. Entries prefixed
> with a number sign are from JGA as my simulator doesn't support them.[1]
>
> The simulator uses full ballots, so Smith//DAC is the same as
> Smith//DSC. If truncation would make the method more resistant, that's
> not reflected here.
>
> 0.698 *Borda
> 0.668 #Approval (from JGA)
> 0.545 Condorcet//Borda (Black)
> 0.480 Copeland//Borda (Ranked Robin)
>
> 0.417 Plurality
> 0.417 Smith//DAC
> 0.412 *BTR-IRV
>
> 0.350 Baldwin
> 0.333 Raynaud (Gross Loser Elimination)
> 0.333 Schulze(wv)
> 0.332 Minmax(wv)
> 0.321 Ranked Pairs(wv)
>
> 0.075 Woodall, Schwartz-Woodall
> 0.074 RCIPE
> 0.074 IRV
> 0.074 Benham
>
> I've included Borda to show that my results are similar to James Green
> Armytage's. (Compare also the results minmax results.) In addition, I've
> included BTR-IRV to see how well it would do. Too bad it didn't do
> better, though...
>
> My simulator show higher manipulability for IRV and the Condorcet-IRV
> hybrids than JGA's simulator did. I think this comes down to that my
> simulator is more thorough and thus is able to uncover more
> nonmonotonicity- and pushover-related strategies.
>
> Finally, I'm working on the cardinal methods, but the devil's in the
> details so it's taking a lot longer than expected. More about that when
> I've solved it. But my preliminary tests put Smith-Range around 0.5 and
> STAR as worse than this. Unnormalized (fixed scale) Range, though not a
> poll method, even does worse than Borda. And if the preliminary tests
> give some indication, all the Range/Score-based methods do worse than
> Plurality.
>
> -km
>
> [1] Green-Armytage, James (2011). "Four Condorcet-Hare hybrid methods
> for single-winner elections". Voting matters (29): p. 7;
> https://www.votingmatters.org.uk/ISSUE29/I29P1.pdf
> ----
> Election-Methods mailing list - see https://electorama.com/em for list
> info
>
KM
Kristofer Munsterhjelm
Tue, May 14, 2024 3:57 PM
On 2024-05-03 23:18, Michael Ossipoff wrote:
Then Plurality is better than Black & Score; & Benham & Woodall are no
better than IRV; & IRV is 4 times better than the best Condorcet methods?
Of course JGA’s results lead to similar questions.
Doesn’t this bring into question the meaningfulness & usefulness of
manipulability as a measure of merit?
IRV has an incomparably worse strategy problem than the best Condorcet
methods.
Plurality is incomparably strategically worse than Approval.
Benham & Woodall, as everyone would agree, significantly improve on IRV.
I think part of this can be answered by thinking about just what the
manipulability measure, well, measures. It gives an indication of how
well the method protects the honest outcome against strategy by the voters.
IRV vs Benham does look strange, and I would like to investigate it
further when I have the time. For instance, it's difficult to reconcile
IRV's problems with not electing Condorcet winners with its low
strategic susceptibility (since the existence of an unelected CW is a
strategy opportunity).
Some of IRV and Plurality's problems come from their strategic
nomination incentive, which my stats don't capture. And another part of
the problem is that, even if IRV and Benham are equally good at
defending the honest outcome, IRV's honest outcome is much worse than
Benham's to begin with. (Similarly, Approval and the manipulable
Condorcet methods have better honest outcomes than Plurality.)
But the broader patterns seem to be more understandable.
That Approval and Score are on the high end makes sense to me because
strategy (watching the polls) is such an integral part of the greater
dynamic. Anybody who looks at the polls and then focuses his cutoff to
maximize the effect will have a good chance of changing the outcome, and
reducing a fully ranked non-dichotomous ballot down to an approval-style
ballot to begin with is somewhat of an art.
Someone on reddit said: "I would never vote in an Approval election
without reviewing all the polls, but wouldn't care in a Baldwin's
election. It's not really about the raw complexity of the strategies
itself, but their relevance."
So what I would take from the manipulability values is that we should
try to find a method that both has good honest outcomes, and is
resistant to strategy away from those honest outcomes. IRV fails the
former; the cardinal methods fail the latter.
Someone might say "just sum up the utility of the worst candidate that
could be elected by strategy, then". But I think that there's a drawback
to strategy in itself. Intuitively "you shouldn't need to look over your
shoulder all the time". Just the effort of adapting your vote to the
strategy can deter.
(And there's value in having few strategies available, because then
there are fewer ways things a misjudged strategy could blow up in
everybody's face.)
-km
On 2024-05-03 23:18, Michael Ossipoff wrote:
> Then Plurality is better than Black & Score; & Benham & Woodall are no
> better than IRV; & IRV is 4 times better than the best Condorcet methods?
>
> Of course JGA’s results lead to similar questions.
>
> Doesn’t this bring into question the meaningfulness & usefulness of
> manipulability as a measure of merit?
>
> IRV has an incomparably worse strategy problem than the best Condorcet
> methods.
>
> Plurality is incomparably strategically worse than Approval.
> Benham & Woodall, as everyone would agree, significantly improve on IRV.
I think part of this can be answered by thinking about just what the
manipulability measure, well, measures. It gives an indication of how
well the method protects the honest outcome against strategy by the voters.
IRV vs Benham does look strange, and I would like to investigate it
further when I have the time. For instance, it's difficult to reconcile
IRV's problems with not electing Condorcet winners with its low
strategic susceptibility (since the existence of an unelected CW is a
strategy opportunity).
Some of IRV and Plurality's problems come from their strategic
nomination incentive, which my stats don't capture. And another part of
the problem is that, even if IRV and Benham are equally good at
defending the honest outcome, IRV's honest outcome is much worse than
Benham's to begin with. (Similarly, Approval and the manipulable
Condorcet methods have better honest outcomes than Plurality.)
But the broader patterns seem to be more understandable.
That Approval and Score are on the high end makes sense to me because
strategy (watching the polls) is such an integral part of the greater
dynamic. Anybody who looks at the polls and then focuses his cutoff to
maximize the effect will have a good chance of changing the outcome, and
reducing a fully ranked non-dichotomous ballot down to an approval-style
ballot to begin with is somewhat of an art.
Someone on reddit said: "I would never vote in an Approval election
without reviewing all the polls, but wouldn't care in a Baldwin's
election. It's not really about the raw complexity of the strategies
itself, but their relevance."
So what I would take from the manipulability values is that we should
try to find a method that both has good honest outcomes, and is
resistant to strategy away from those honest outcomes. IRV fails the
former; the cardinal methods fail the latter.
Someone might say "just sum up the utility of the worst candidate that
could be elected by strategy, then". But I think that there's a drawback
to strategy in itself. Intuitively "you shouldn't need to look over your
shoulder all the time". Just the effort of adapting your vote to the
strategy can deter.
(And there's value in having few strategies available, because then
there are fewer ways things a misjudged strategy could blow up in
everybody's face.)
-km
