[EM] Thoughts on a nomination simulation

[Kevin Venzke]

Hi Kristofer,

--- En date de : Mer 16.6.10, Kristofer Munsterhjelm <km-elmet at broadpark.no> a écrit :
> I think that a nomination simulation would have to be more
> complex, to take feedback into account. Candidates would
> position themselves somewhere in opinion space, then move
> closer to the winners depending on the outcome of the
> simulation (and possibly decide to drop out if this would
> elect a candidate closer to their position).

It basically works (or will work) like this except I plan to have the
movement be in a random direction. If the movement is unsuccessful then
the change is undone and the next candidate gets to "go." It's an issue
but hopefully not an insurmountable one that the proper place for the
candidate to stand may be nowhere near where they are.

> Even so, the simulation would fail to catch certain aspects
> of the election cycle itself. Consider a two party state
> under FPTP. In a pure opinion-space analysis, the two
> parties would converge on a common point (the "center") in
> an effort to eat into each others' voters, yet in reality
> that doesn't seem to happen - the Republican and Democratic
> parties appeal to different voters.

A possible theory: They could not converge to the center because a
third candidate could decide to sit on the outer side of one, and still
be somewhat viable. So, a candidate needs to be far enough from the center
to discourage a rival nomination from the same side.

> Changes in voter sentiment might be able to handle some of
> that problem; by having voters change their opinions between
> elections, candidates know not to get too specialized
> (because it takes time to move about in opinion space). That
> would also limit stagnation in even advanced systems: if you
> have a Condorcet method and a party places itself at the
> (static) median voter, the game is over and all the other
> parties can just as well go home.

Well currently the median is not static. On average it is static, but in
a given election it could move a bit.

> There are other effects as well: Parties and candidates
> might also slide into corruption unless checked by
> competition. One could model that by a candidate wanting to
> both be elected and to be placed at a certain point in
> opinion space (individual corruption), or by candidates
> being attracted towards a certain area in opinion space
> (coordinated corruption, e.g. by lobbying).

Those are definitely interesting ideas. One would have to figure out the
formula that decides where increasing "electibility" is no longer desirable
to a candidate.

> Candidates may
> be of use (as opposition), even if not elected - not sure
> how to model that; and the candidates, particularly
> organized ones, may choose to employ strategy if doing so is
> feasible (as the New York parties did under STV) - I'm not
> sure how to model that, either.

I expect to have candidates behave naively since I don't want to pretend
to know beforehand what kinds of "transformations" could be helpful to
a candidate. I really hope to see odd equilibria in some methods that
have never been considered.

The idea of a candidate being nominated to improve expectation from the
election, rather than getting that candidate elected, raises the issue
of whether candidates are mainly concerned about being elected, or about
the expectation for their supporters. Also, whether "withdrawal" from
the election means that the candidate actually withdraws, or that the
voters simply decide that they will ignore this candidate as unhelpful.
In reality it's probably a combination of both.

Kevin