[EM] James: Strategy definitions and criteria, 29 March, 0521 GMT

[James Green-Armytage]

This is James G-A replying to Mike Ossipoff, on the topic of strategic
voting... (When I write "James:" before a bunch of quoted text, that means
that the text was originally written by me, and quoted by Mike. When I
write "Mike:" before a bunch of quoted text, that means that I am quoting
Mike.)

Mike:
>
>No, I didn't say that Blake uses "burying" differently from its usage in
>funerals, or even that he uses it differently from its physical meaning.
>I 
>said
>that he uses it differently from the meaning that it always has, its
>general
>meaning, without regard to any one particular context.
>To bury something means to put it under something else, or to conceal it. 
>That's
>exactly the meaning of burying that I use when I refer to favorite-burial
>strategy in Plurality or IRV.
>If that isn't burying to Blake or to you, then you're using a different 
>meaning
>of burying, different from what the word means to others.
>But I have no complaint if you or Blake invent new meanings for words.
>
	Burying means to place one thing under something else. Let's say that
your sincere preferences are Nader>Camejo>Kerry>Bush, but you vote
Kerry>Nader>Camejo>Bush, in order to decrease Bush's chance of winning. In
this case, I argue that it makes less sense to say that you are burying
Nader and Camejo under Kerry, and more sense to say that you are raising
Kerry above Nader and Camejo. This is a useful distinction that Blake's
terminology helps us make.
	Why does it make more sense to say this? Because if you are "burying"
Nader, it seems to imply that your purpose is to change the probability of
Nader's being elected. Actually, that isn't your purpose, although it may
be a side effect. Your purpose is to improve Kerry's chance of being
elected (thus decreasing Bush's chance of being elected), hence it makes
sense to say that you are raising Kerry, rather than burying Nader. 

Mike:
>>Excuse me, James. Give me a grounding in the basics :-)

James:
>
>	Read Blake's EMR page at Condorcet.org. I don't subscribe to all of his
>definitions, and I don't agree with him on all controversial issues (e.g.
>margins vs. wv), but I think that some of his terms (e.g. burying,
>compromising, push-over, crowding) form a useful basis for understanding
>strategic possibilities in different methods.
>
Mike:
>Thank you for that grounding in the basics. :-) If Blake's website is the
>basics, then I fully admit that I'm not grounded in the basics.
>
	No, Blake's website in itself isn't "the basics". But it contains many
useful definitions, a few which form a useful basis for strategy
discussion, as I mentioned above. There are three pages of Blake's site in
particular that I suggest you have a look at. They are all quite brief and
condensed.
http://condorcet.org/emr/defn.shtml
http://condorcet.org/emr/methods.shtml
http://condorcet.org/emr/criteria.shtml
>
Mike:
>
>I've repeated this very many times, including a few times during the last 
>few days, but apparently it's necessary to repeat it again for you:
>Your emphasis on methods' immunity to strategy is barking up the wrong
>tree. 
>Plruality is immune to what you call burying strategy. So what? The
>reason 
>why Plurality is widely recognized as the worst is because, though it is 
>immune to what you call burying strategy, Plurality, given the situation 
>that millions of voters believe exists, strategically forces voters to
>bury 
>their favorite.
>The problem is voters' need to reverse preferences or abandon or bury
>their 
>favorite. That's why Plurality is widely recognized to have an especially 
>serious strategy problem even though Plurality is immune to what you call 
>buring strategy.
>I'm not interested in immunity to what you call burying strategy. I'm not 
>interested in methods susceptibility or immunity to strategy. I'm
>interested 
>in the extent to which they strategically force voters to abandon their 
>favorite and conceal what they really want.
>I find that it's necessary to repeat the same things so often that I
>should 
>just write these answers into a FAQ, and post the FAQ every time you or 
>someone like you repeats the same questions and mis-statements.

	That's not necessary in this case. I was already aware of your point of
view regarding the relative importance of "offensive" versus "defensive"
strategy. (I also get annoyed when it seems I am repeating myself more
often than necessary.) However, the fact that I understand your point of
view doesn't necessarily mean that I agree with it.
	Translating your argument into terms that I can readily work with, you
seem to be saying that we shouldn't worry about the burying strategy in
itself, but only about the compromising strategy, and the
counterstrategies needed to fight the burying strategy.
	First of all, I agree with you that the compromising strategy is a
serious problem. Plurality has an extremely nasty compromising strategy
incentive, two round runoff has a compromising incentive that is slightly
lessened but still bad, IRV's is slightly less again but still bad.
Condorcet methods still have some compromising incentive, but it is
minimal. And yes, this should make a huge difference in people being able
to make their sincere favorites known, and in allowing a profound
transition from LO2E candidates to sincere greater-of-many-goods
candidates. In short, I strongly agree with your goal to minimize the
compromising strategy.
	We can observe the harmful effects of the compromising strategy, and we
can see the need to minimize the incentive for it. But what about the
burying strategy? Where can we observe its harmful effects? The answer is
that we can't, because methods that are susceptible to it are not
currently used for major public elections. Hence, the burying strategy is
not a problem in elections today, but it might become a problem if
Condorcet methods (or approval, Bucklin, etc.) are adopted. In order to
understand the harmful effects of the burying strategy before
burying-vulnerable methods are adopted, we need to use our foresight, our
imagination. We need to take steps to prevent serious burying problems
before they occur, or risk discrediting Condorcet systems in general.
	Why, in your opinion, do we not need to worry about the burying strategy?
If a group of voters is able to change the outcome to the ideological
polar opposite of the sincere CW by means of a burying strategy, is this
not a serious problem? Of course it is. Can we take steps to prevent it?
Yes, we probably can in most cases, but in doing so, we acknowledge that
the burying strategy is worth worrying about. This brings us to the issue
of counterstrategy. What counterstrategies can voters use to try to make
burying strategies unprofitable? How effective are these strategies, and
how risky are they in their own right? 
	These are questions that we have discussed in detail already, so I know
that you are at least somewhat interested in them. If you are able to show
that particular Condorcet methods are not particularly vulnerable to the
burying strategy, that's great, but it doesn't mean that the question of
vulnerability itself is unimportant ("barking up the wrong tree").
	Condorcet methods (in place of plurality, runoff, IRV) minimize the
compromising strategy, but introduce the burying strategy. As long as we
choose Condorcet methods that are relatively good at keeping burying under
control (e.g. not margins!), I argue that this tradeoff is clearly
worthwhile. However, when arguing for the adoption of Condorcet, we must
recognize that this is at issue. If we conceal the issue, I argue that we
are just as intellectually dishonest as IRV advocates who advertise that
IRV "eliminates the spoiler problem" and "ensures majority rule".
>
Mike:
>>I don't claim to be able to tell you what compromising-compression means,
>
James:
>
>	That's too bad, since I gave you the date of the posting where I defined
>it. That's 3/29/04. But anyway, here's the direct link:
>http://lists.electorama.com/pipermail/election-methods-electorama.com/2004-March/012515.html
>	In that post (one year ago tomorrow) I discussed the difference between
>your criteria and Blake's criteria in some depth. Hence, it's closely
>related to our current discussion, and I request that you read it.
>
Mike:
>I'll check it out, but does it really say anything different from what 
>you've been saying lately?
>
	Yes. For one thing, it will tell you what "compromising-compression"
means...

Mike:
>
>You know, to discuss the difference between my criteria and Blakes, I'd
>have 
>to be conversant abouit Blake's criteria. I can't say that I am. 

	I can see no good reason for you not to be. If you are interested in
engaging in discussion on this list, that sometimes means talking about
someone else's ideas besides your own.

James:
>
>while your
>concepts are better for later study, built on the previously-established
>foundations.
>
Mike:
>So you're suggesting that my criteria are built on a foundation
>previously 
>established by Blake.

	Not at all. I was suggesting that for example if one was to write a
textbook dealing with tactical voting, it would make sense to begin with
Blake's criteria (e.g. burying and compromising) and then move on to your
criteria (e.g. SDSC, GSFC) in a subsequent chapter or subchapter, along
with your definitions of "offensive" and "defensive" strategy.

Sincerely,
James
http://fc.antioch.edu/~james_green-armytage/voting.htm