[EM] serious strategy problem in Condorcet, but not in IRV?

[James Green-Armytage]

Dear Eric,

I wrote:
>>The outcome is unpredictable. It is quite possible that C will be
>elected,
>>despite the fact that he so clearly does not deserve to win. This is not
>a
>>pleasant scenario at all from the point of view of democracy, utility,
>>majority rule, public trust in government, etc.

You replied:
>
>Why?
>
>The voters you are describing are no longer interested in democracy, 
>majority rule, etc.
>
>When there are such blatant, unapologetic attempts to manipulate the 
>system, no voting system can possibly save them.

I reply:
Maybe so, but I like to take game theory analyses pretty seriously when
designing a political or economic system.
Game theory assumes that the agents involved aren't interested in the
overall fairness of the system as much as they are interested in getting
their way. A good system from a game theory point of view is one in which
agents act according to their own personal desires, potentially desires
which conflict with each other, yet the overall result is desirable for
society as a whole.

Looking at the current state of American politics, I would say that many
of the agents involved, at least on the high government side of the glass,
show a lot more interest for themselves, their party, their class, their
group, etc., then they do for democracy in general. The voters, perhaps,
are perhaps somewhat less self-interested, but not entirely by any means.
For example, the billionaire who stands to gain from a Bush tax cut or
deregulatory law, and on the other hand maybe a teacher who stands to get
a raise or better funding for their school if the other guy wins.
Whatever. Even when there isn't direct self-interest involved, I think
that the animosity between Democrats and Republicans at present is enough
that many of them would be willing to vote strategically to try to bury
the candidate from the other party. 

I am told that when STV was used for school board elections in New York,
parties (or in-groups of some sort) would actually come up with some
pretty elaborate strategies to increase their voting power, and then call
up their supporters and tell them to vote a certain, insincere, way. 

Perhaps the best thing we could do, if we wanted to use Condorcet on a
public level would be to make sure that conspiring to such violently
strategic voting would be a matter of political shame, or even illegal. I
am not saying that it is necessarily a fatal problem for Condorcet (Monroe
seems to think so, but that is why I say he overstates his case), but I am
saying that it should be looked at carefully.

sincerely,
James