[EM] Some brief campaign argument

[LAYTON Craig]

>There seem to be three main reasons for believing Approval is the best
>electoral method - 1) a sincere vote is always the best strategic vote; 2)
>approval elections will elect a higher SU winner than any other method/s in
>a real world scenario.

I left out number 3) which was approval's simplicity (related to the
argument that it is a better public proposal).  As I'm pointing it out now,
I might as well briefly discuss it.  Approval is certainly the easiest of
the decent voting methods to count and to explain.  There are some economic
advantages in terms of counting votes and not having to radically change
voting equipment or proceedures if moving from plurality to approval.  I'm
willing to conceede that Approval certainly has this going for it.

However, it isn't necessarily true that Approval is simpler to understand or
to vote.  Sure, the instructions are simple (vote for as many candidates as
you like), but it isn't easy for voters to understand how they should vote -
for how many candidates, what's the best strategy, how should I be using the
polling information etc.  I would have trouble explaining to someone how
they should be voting in approval (beyond "just vote for the candidates you
like").  In Ranked Pairs, for instance, it is a simple matter.  Put your
favourite first, and keep going - stop at any time if you get sick of it.
Of course it won't be the best strategy 100% of the time, but it is close
enough, certainly much closer than any similarly simple advice for an
approval election.

There is also the potential for mass dissatisfaction from voters who don't
use the correct strategy, say in a close three way contest where a
significant chunk of voters have a sincere preference A>B>C, Approval vote
AB, but an election result where B beats A by a handfull of votes.  If it is
clear that A would have won in a pairwise contest between the two (and the
three), Approval voting will become unpopular very quickly, further
diminishing its claims of being the best SU voting system.  It is much more
likely in Approval that your vote will be irrelevant, by not expressing a
preference between the frontrunners.  This is much worse for utility than
very occasionally choosing a better candidate.