[EM] To Bill Lewis Clark, re: Approval, CR, & IRV

[Bill Lewis Clark]

David Gamble wrote:

> On the EM list there is much lengthy discussion of voting strategy,
> strategic voting and the like.

I've gathered as much :)

> To gloss over lots of details it is generally presumed that voters
> behave rationally and vote strategically to maximise the utility of
> their outcome in an election.

I think that presumption is almost undoubtedly false, in the general case.
 I suspect it's based on some misleading observations:

(1) Under our[*] current plurality system, most voters cast their ballots
for one of the two front-runners, which happens to be the optimal
strategy.

(2) In situations where some alternative system is used (selecting the
Secretary General of the UN, mathematical and engineering professional
societies, the Debian Linux development forum, etc.) members often vote
strategically.

With regards to (1), I think what's really happening is that most people
are choosing a "brand" rather than implementing any actual strategy.
There is significant peer pressure to vote for one of the major parties,
regardless of the strategic merit in doing so.  The spoiler effect is
surely one of the main contributing factors in maintaining the two-party
duopoly -- but it's not the *only* factor.

Regarding observation (2), I'd simply point out that these aren't your
"Average Joe" (or "Jane"... or "Juan", etc.) voters, and are far more
likely to be savvy about the mathematical inner workings of various voting
systems (or, in the case of the UN, at least will have members of their
advisory teams who are well-versed in voting strategies.)

Even in countries where voting systems other than plurality are in general
use, strategic voting is far from universal (and in many cases, when it is
used it is done so at the urging and direction of party spokespeople --
which is hardly what I'd call "rational" behavior.)

Furthermore, I'd like to point out that even if a sizable majority of the
voting population *were* to vote strategically, their strategy would
necessarily take into consideration the effects of those voters who
*don't* vote strategically.  In particular, the ratio of strategic to
non-strategic voters is itself a major point of consideration, in devising
a voting strategy.

Finally (to get back to my main point), since the behavior of
non-strategic ("sincere") voters can differ greatly depending on the
particular voting system used, it simply seems *wrong* to argue that
approval voting and cardinal ratings are strategically equivalent.  In the
real world, strategic voters will be forced to follow different strategies
under each system, because of the different ways sincere voters will
behave.

-Bill Clark

[*] I use terms like "our" to refer to citizens of the USA.  I'm entirely
unsure what the demographic makeup of this list is, and I apologize for
any offense my terminology might cause.  If it's an issue, just let me
know and I'll try to change it.

-- 
Dennis Kucinich for President in 2004
http://www.kucinich.us/