[EM] Why the concept of "sincere" votes in Range is flawed.

[Michael Poole]

Abd ul-Rahman Lomax writes:

> And now that rarity from me, an original post....
>
> Approval Voting is a special case of Range, with rating values
> restricted to 0 and 1. When Brams proposed Approval, it was as a
> method free of vulnerability to "tactical" or "strategic" voting,
> i.e., voting with reversed preference in order to produce a better
> outcome. And, indeed, both Range and Approval are immune to that,
> i.e., there is no advantage to be gained by it, ever (at least not in
> terms of outcome).
>
> The proponents of other methods attacked this by redefining -- without
> ever being explicit about it -- the meaning of strategic
> voting. Because the concept was developed to apply to methods using a
> preference list, whether explicit on the ballot or presumed to exist
> in the mind of the voter, a strategic vote was one which reversed
> preference, simple. But with Approval and Range, it is possible to
> vote equal preference. Is that insincere if the voter has a
> preference? The critics of Range and Approval have claimed so, and
> thus they can claim that Range and Approval are "vulnerable to
> strategic voting."

Your definition is wrong.  A strategic vote is one that is not
representative of the voter's honest views or ideal outcome.  When
using strictly ranked systems (where no ties are allowed), the only
possible form of insincerity is order reversal.  When using approval
and range voting, preferences may be insincerely magnified or diluted,
in addition to being reversed.

As a thought experiment, consider the case where I would score three
candidates as 100, 50 and 0 on a uniform scale.  If I know that the
first two candidates are close in the polls, I may vote for them as
100, 10 and 0 so that my preferred candidate's chance of winning is
increased.  This is a strategic vote in the usual sense.  You attempt
to redefine "strategy" so that it is not called one.

Rambling about ideal abstractions, inevitable voter knowledge, and so
forth does not change that it is a distortion of my honest ratings
based on desired outcome and beliefs about other ballots.  Strategic
voting works *only* in the case of (believed) knowledge about how a
significant number of other voters vote.

If you delude yourself into thinking otherwise, and on that basis
convince yourself that range voting does not suffer from -- or even
permit -- strategic voting, you will only undermine your own
credibility.

Michael Poole