[EM] Strategy and Bayesian Regret

[Jameson Quinn]

2011/10/28 Kevin Venzke <stepjak at yahoo.fr>

> Hi Jameson,
>
> I am a little short on time, to read this as carefully as I would like, but
> if you have a
> moment to answer in the meantime:
>
> --- En date de : *Ven 28.10.11, Jameson Quinn <jameson.quinn at gmail.com>* a
> écrit :
>
> voting is best. But how do you deal with strategy? Figuring out what
> strategies are sensible is the relatively easy part; whether it's
> first-order rational strategies (as James Green-Armytage has worked out<http://www.econ.ucsb.edu/~armytage/svn2010.pdf>)
> or n-order strategies under uncertainty (as Kevin Venzke does)
>
> 3. Try to use some rational or cognitive model of voters to figure out how
> much strategy real people will use under each method. This is hard work and
> involves a lot of assumptions, but it's probably the best we can do today.
>
>
> As you might have guessed, I'm arguing here for method 3. Kevin Venzke has
> done work in this direction, but his assumptions --- that voters will look
> for first-order strategies in an environment of highly volatile polling data
> --- while very useful for making a computable model, are still obviously
> unrealistic.
>
> [end quotes]
>
> I am very curious if you could elaborate on my assumption that voters will
> "look for
> first-order strategies in an environment of highly volatile polling data."
> I'm not totally
> sure what you mean by first-order vs. n-order strategies,
>

First-order strategies are strategies which work assuming all other
factions' votes are unchanged. Second-order strategies either respond to, or
defend against, first-order strategies. I guess that your system, through
iterated polling, deals with "respond to", but it is incapable of "defend
against".


> and whether your criticism
> of unrealism is based on "voters will look for..." part or on the "highly
> volatile polling
> data" part.
>

Some of the former (lack of defense), but mostly the latter.

Also, it's not so much a criticism, as a pointer for what comes next. You
have *absolutely* gone farther than anyone else I know of in exploring the
motivators and consequences of strategy across voting systems, and if my
appreciation of that fact didn't come through, I'm sorry. (Green-Armytage
has some answers you don't about motivators, and Smith's IEVS has some about
consequences, but your work is by far the best for combining the two.)


> I wonder if this volatility is a matter of degree or a general question of
> approach.
>

Well, I've never seen you try to justify the volatility in terms of realism.
It's a computational trick, to prevent excessive equilibrium, from what I
can tell. That is, your unrealistic (perfectly rational in some ways but
utterly lacking in any meta-rationality) voters may need this unrealistic
assumption to give more-realistic answers, and if so, then "fixing" this one
issue is not the answer. (If there were no volatility, I think that your
system would end up comparing a lot of 100%/0% numbers, which doesn't
discriminate very well between systems.)


>
> I want to note in case it's not clear that when I talk about what
> strategies voters are
> using, that is just a reporting mechanism that has awareness of the
> relationship
> between voters' sincere preferences and how they actually voted. The voters
> have
> no idea what they are doing in strategic or sincere terms.
>

Yes, I understand that.

Cheers,
Jameson
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