[EM] Voting methods & utility

[Bart Ingles]

LAYTON Craig wrote:
> 
> For some time, I've been seeing comments relating to maximising utility in
> voting systems.  Very rarely have these comments had anything to do with
> utility/utilitarianism.  As a committed utilitarian, I would like to clear a
> few things up;
> 
> The preferred candidate (whichever way you determine who this is) is not
> necessarily the best candidate.  It is impossible to design a voting system
> to select the best candidate.

Agreed -- the goal should be to reflect the will of the voters.


> Systems like Borda, cardinal ranking &c. are NOT utilitarian.  They have
> nothing to do with utilitarianism.  There might be a crude 'preference
> satisfaction = utility' argument, but this isn't really adequate.  These
> voting systems normalise preferences (so that everyone's top & bottom score
> is the same, no matter how strongly they feel about the candidates).  Also,
> the consequences of a non-majoritarian candidate winning are severe enough
> to mitigate any utility advantage these systems might have.

Also agreed -- no voting system can reflect true aggregate utility and
still be fair.  The reason is that there has to be some equality in
voting power between voters.

The second point -- that a non-majoritarian candidate is undesirable --
is a good reason not to collect data unless you're sure you can use it
fairly & accurately to reflect the will of the voters.  Systems using
rankings are constrained by the need for self-consistency, using some
standard such as Condorcet's or Borda-symmetry.  The only way to "bend"
the results to make them better reflect strength of preference is to
rely on strategy.


> There is perhaps some argument about, say, weighting voting systems to
> eliminate the most disliked candidates while maintaining majoritarianism.
> This might be utilitarian, as there are strong reasons to suggest that
> avoiding disutility should be prioritised over maximising utility.
> But, again, this only works well when voters are voting sincerely.

No disagreement here either.


> Elected representatives do not always make decisions in such a way as to
> maximise utility.  There is no reason to suggest that changing the way these
> representatives are elected will change the way in which they make
> decisions.  The task of utilitarians (and indeed most political
> philosophers) is to challenge the decisions that representatives make.  How
> those representatives get to power does not significantly affect
> utilitarianism, unless the system that got them there causes some
> significant disharmony (or the reverse).  There are few proposed systems
> that do this (perhaps non-majoritarian systems are the only ones).

So what you're saying is that 'utilitarianism' will never be used in its
correct context on this list.  In which case I don't see much harm in
using the term 'utility' in a way that it has frequently been used (or
misused) in connection with voting systems.

-B


> I would ask people to think twice about referring to utilitarianism / social
> utility &c. when discussing voting systems.