[EM] Top Two Runoff versus Instant Top To Runoff

[Kevin Venzke]

Hi Forest,

--- En date de : Sam 22.11.08, fsimmons at pcc.edu <fsimmons at pcc.edu> a écrit :
> It seems to me that Top Two Runoff might be more
> manipulable than the instant version of the same, since
> voters could vote insincerely in the first round without
> having to worry about that messing up their choice in the
> other stage.
> 
> I would be interested in your thoughts on this matter.

Not sure I follow. I guess you mean that Chirac voters could instead vote
for Le Pen, forcing voters on the Left to support Chirac in the second
round when under IRV they would not have seen any need to support Chirac
over Le Pen.

That's possible, but I think it's far more likely that this mechanic works
in a positive way. Under IRV the possibility that a too-obscure candidate
(or a candidate in the same vein as a frontrunner but without official
backing) won't receive any lower rankings would be a serious obstacle. 
Under TTR his supporters can try to place him in the top two with much 
less risk, since if he makes the top two and really is preferable to the 
other top-two candidate, other voters can provide their support later, in 
the second round.

I think both the good and the bad of TTR come from reduced nomination
disincentive and with this the ability to vote more *sincerely* (in a
sense: If they were "insincere" otherwise it may be because the candidate
did not run).


I think the following preserves most of the good and gets rid of most of
the bad.

How does FPP stay limited to two viable candidates? You lose nothing by
voting for 2nd place, and a vote for 3rd place is really a vote for 1st
place.

So change TTR to make it so that you lose nothing by voting for 3rd place
(what it already has), and a vote for *fourth* place is really a vote for
1st place.

In other words: The first-round winner is automatically elected as long
as he has more votes than second and third place combined. He doesn't have
to beat candidates who do worse than that.

More consolidation (i.e. to get down to three candidates) before the
first round should, I think, make it more likely that the second round
isn't always between the same players.

This fails if it can't be expected that one candidate could get enough
votes to beat the next two. But how likely is that? How often is FPP that
fragmented? All it would take is for one candidate to develop some 
momentum, and it would become too risky to not consolidate.

We also still have FPP's spoiler problem, though not as bad.

I also like to consider using this first round as a filter to get us to
a second round that uses a completely different election method (esp.
one that isn't defined for more than three candidates, or is too
manipulable if nominations can be made directly).

Kevin Venzke