[EM] Strategic polls in Approval

[Abd ul-Rahman Lomax]

At 01:59 PM 12/30/2006, Juho wrote:
> > This is an election where there is something close to a three-way
> > tie. That's rare, for starters.
>
>This strategy requires at least three candidates that can be claimed
>to be leading candidates.

Exactly. And therefore the simple "vote for the preferred *one* among 
the front-runners" strategy does not properly apply. Voters using it 
are already astray. The polls merely take them a little further astray.

>In two-party countries having three candidates of about equal
>strength would be exceptional.

Indeed.

>  Im multi-party countries or if parties
>have more than one candidate that is not exceptional.

That's right, though the latter situation requires that the party in 
question have two-thirds of the electorate as supporters, 
effectively. Such a party would not be likely to run two candidates, 
for if it did, under some systems, it would risk losing the election. 
However, with Approval, it could. And if there were a third candidate 
with parity with the two from the party, party supporters would be 
well advised to vote for both the party candidates. If even half of 
them do, there is no chance for that third candidate. What would be 
strange, indeed, would be for significant party supporters to vote 
for the third candidate, and that is exactly what it would take for 
the poll strategy to have an effect....


> > I don't think the poll would have much effect. For this strategy to
> > work at all, the election has to be close, there must really be
> > some doubt about which of the three candidates will actually turn
> > out to be in third place. So voters will consider that.
>
>In the example it was ok if voters were uncertain of which opinion
>polls are reliable. The plotters were happy with the confusion (as
>long as they could avoid having polls where A was not among the
>leading candidates).

How could they avoid that? They can't control all the polls, and if 
they can fake polls, so can someone else.

My point is that this strategem depends upon voters using a voting 
strategy which is inappropriate for the three-way race that is 
involved. That strategy is not designed for such races, it is 
designed for races where there are two and only two frontrunners.

In the race described, there are not two frontrunners, there are 
three. A "frontrunner" is a candidate with a reasonable chance at 
winning the election. That is apparently true of all of these. In 
order to take B out of a true frontrunner position, the poll must 
*drastically* distort B's position, it is not merely enough to reduce 
it to third place. Third place if it is close to second and first is 
still a frontrunner position.

In other words, by assuming that "frontrunner" refers only to the top 
two candidates, simply because most analyses have assumed and have 
been considering such elections, the strategem appears to be 
feasible. But who is going to advise voters to follow a 2-frontrunner 
strategy when there are three candidates close to parity?

And, as I've noted, provided that the election requires a majority 
approval to win, there is a zero-information strategy that is quite 
safe, and I described it. I'd suggest that strategy as the general 
one to follow, not the preferred of top two plus everyone else better 
than that one.

>The strategy works (partially) even if only some voters get fooled.
>If A and B were close to equal then already a small change may bring
>victory to A.
>
> > Where there are three frontrunners, this strategy does not exactly
> > apply. That's the situation proposed. There are really no
> > frontrunners in this race.
>
>In the example the first (correct) poll showed that A and B had more
>support than C (but only so much that the A supporters could claim
>that also C could be a lead candidate).

Right. So all are close to winning. Now, is this "first preference" 
polling or "approval" polling?

> > And poll results are *not* essential for good Approval Voting. I
> > stated an alternative strategy that could easily be used in a three-
> > way race, and I suggest it is an appropriate one there.
>
>The Approval optimal strategy descriptions refer to the poll or
>expected results of the election. That opens one possibility to
>influence how voters vote - at least in theory.

Sure. And you can also influence voters by lying to them about many 
different things, with probably more effect than lying to them about 
poll results. Anyone can take polls, so seriously distorted polls 
results will merely make those who release them look bad. And minor 
distortion should properly not affect voters, because minor 
distortion cannot convert a frontrunner into a candidate with no 
reasonable chance of winning. *That's the definition of front-runner, 
actually, front-runners are those with a reasonable chance of 
winning, the winner is almost certain to come from the class of 
frontrunners, exceptions would be rare.

>I don't claim that this strategy would somehow dramatically change
>the way I see Approval. But it is good to cover also these
>possibilities and prepare for them, and to make the voters and
>politicians and media aware of these risks.

There would be plenty of time. Note that this hazard is *worse* under 
present FPTP systems than it is with Approval. With Approval false 
polls would do far less damage. Under FPTP, if you can convince a 
voter that their favorite is unlikely to win, you can influence them 
to vote for someone other than their favorite. With Approval, if you 
falsely convince them of that, they still will vote for their 
favorite, you are only, possibly, influencing them to place their 
approval cutoff in a different place.

I don't think that the analysis of the stratagem's effect was 
thorough. To be thorough, one should consider preference strengths, 
they affect how the voters will respond to the misinformation. Now, 
if voters have a preferred candidate, I'd think they would listen to 
that campaign's releases about how the election was going. They would 
not be terribly likely to be influenced for strategic voting purposes 
by releases from the campaign of another candidate, not even by 
supposedly public, disinterested polling organizations.

I don't think it is possible to distort the polls sufficiently that a 
rational voting strategy would be seriously affected. It is only a 
mindless strategy where voters determine solely who the top two are 
and don't pay attention to another candidate yapping at the heels of 
those two. And who is going to advise voters to vote that way? In the 
context of a true three-way race?

Sure, a candidate might. And, as I've pointed out, that candidate 
just might lose my vote entirely by giving that advice. I don't like 
candidates giving bad advice! Says something about their character or 
intelligence, or both....