[EM] Thoughts on a nomination simulation

Kristofer Munsterhjelm km-elmet at broadpark.no
Wed Jun 16 14:57:17 PDT 2010


Kevin Venzke wrote:
> 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.

The way I was considering would be to start with a bunch of random 
candidates. Run the election. Each candidate then determines whether he 
would have made his side better off if he didn't run, in which case he 
removes himself from further rounds. Then the candidates that remain 
update their position by moving closer to those on its side that are 
above it in the social ordering, subject to possible counterbalancing 
forces (warding off nominations on one's own side, for instance). 
Finally, the voters' opinions change somewhat, to model a change of 
opinion as may happen between elections.

The result would be a sort of attractor/k-means clustering type of 
algorithm, where the dynamics would depend on the method in question.

One might also have new candidates appear - perhaps probabilistically 
depending on distance to closest existing (or recently elected?) candidate.

>> 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.

That is possible. Would primaries encourage that effect? If so, would we 
expect parties in two-party states without voter primaries to be closer 
to each other?

>> 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.

What I was thinking about here is that the median may change in a 
consistent way. For instance, say that someone pulls off a particularly 
large robbery in the country in question; this may shift the voters' 
opinions to the "right/tough justice" area of opinion space; or the 
voters may consider environmental concerns more important than earlier 
and so shift in that direction. Events in the real world can change the 
voter opinion.

In a simulation, I suppose the shifts would be modeled in a fairly 
random manner, since it would be hard indeed to determine which model 
would be most realistic. Perhaps some sort of 1/f noise would work so 
that there is both slight/noisy changes and slow, large, consistent ones.

>> 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.

I imagine electability would be the first priority (excepting idealist 
candidates, but they aren't likely to be corrupted anyway). The 
candidate would reason: better to be elected and make a compromise than 
not make a compromise and not be elected. Within the space of positions 
he can take and still be elected, however, the candidate would tend 
towards a self-serving/corrupted point.

Cartel-like corruption ("what are you going to do, vote for a third 
party?") would be more difficult to model. I'm not sure if they happen 
consciously or if they're just a mutual laziness/implicit agreement by 
both parties, a kind of "I won't lower my prices (approach the voters at 
the expense of my own gain) if you don't lower yours".

>> 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.

That's true; there's no need to burden the system unduly - strategic 
transformations can be implemented later if the simulator works well for 
sincere voting.

> 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.

I seem to recall Nader saying that Gore was as bad as Bush and thus the 
spoiler effect was no problem for him. He would thus be an expectation 
candidate, I think. At the other end, the Republican and Democratic 
parties are definitely in it to win.



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