[EM] STV district magnitude

[James Green-Armytage]

Hello. This is James Green-Armytage, replying to James Gilmour's posting
about STV district magnitudes.


> But if we are looking
>at a national parliament of, say, 120 members, it  would be undesirable
>to elect all 120 from a single national-district.  The principal reason
>is not one of practicality, but rather political consequence.
>Experience has shown that it is politically undesirable to give
>representation down to 1 in 120, as the example of the Israel Knesset
>shows.  In countries using party list systems of PR with national
>aggregation of votes to determine the parties' shares of seats, it is
>common to apply an arbitrary threshold (typically 5%) specifically to
>exclude small parties.  These thresholds are arbitrary (Why 5%?  Why not
>4% or 6%?); it would be more logical to accept the de facto thresholds
>that come with districts - where the sizes of the districts have been
>determined for other, logical reasons.
>
>For this reason I would reject all "extensions" of STV-PR that seek to
>add any aggregation of votes across districts with the aim of
>"improving" the PR. 
	What it it about the Israeli parliament which proves that high district
magnitude is a mistake in general?

>The law of diminishing returns applies to representation in much the
>same way as it applies to many other things.  As the number of members
>per district rises, the proportion of voters NOT guaranteed
>representation falls off very rapidly at first and then progressively
>more slowly.  (This applies to all systems of PR, not just STV-PR.) 
	What are your grounds for saying that there is a diminishing return of
representativeness with greater district magnitude?
	I agree that this might be the case if you just measure whether someone
is represented by whether they get a seat for the party they like best,
but I believe that voters' true preferences are more complex than just a
choice of one party or another, and so I'd say that there is always room
for representativeness to keep increasing at the same rate.
	You have to consider that there might be some ideas or groupings that are
very important to people, but are never concentrated enough to have a
tenth of voter preferences.

>There is also a trade-off between the proportionality of representation
>and the localness of representation.  These two factors pull strongly in
>opposite directions so far as optimal district size is concerned.  In
>some political cultures, real electors attach great importance to
>localness and so it cannot not be ignored. 
	I agree that this is a tradeoff. It seems to me the most important
tradeoff by far.
	Again, electing some candidates in smaller districts and others in larger
districts that encompass the smaller districts is a method of having it
both ways. They could either be part of the same legislative chamber, or
they can form two separate chambers. If nobody wants this, then people
just have to decide on a middle-ground. Maybe they should use Condorcet to
decide. : )
	Actually, the only way of meeting both of these desires at once is to
have a legislature that is just bloody huge. I'm not especially in favor
of that, but it is worth mentioning.


>This is certainly true in
>the UK and in New Zealand. It is much less important in most of
>continental Europe.  I would guess it could be an important factor in
>the USA and in Canada, but I have no first hand experience on which to
>base a firm opinion.
	As far as political culture goes, I live in America, and I consider
myself to be fairly interested in the politics here, but at this point I
don't even know the name of my congressional representative. All I
remember about her is that she is a Democrat who came out with some
phoney-ass statement before the election about how after very careful
consideration she supported the war in Iraq, that she regretted the need
for mass violence but she thought it was too pressing a matter of national
security to let Hussein keep cooking up those WMD's. So I'd say that I am
not too enthusiastic about being her constituent.
	Another weird thing about America is that, despite the fact that it is a
very big country, much of the culture takes place on a national scale. I
believe that this applies to political culture as well. I think that
people pay surprisingly little attention to local and state politics, and
what little attention gets paid to politics mostly goes straight to the
national level.
	People running for nationwide congress seats might receive more attention
than those running for region-specific seats, because it would be easier
for the national mass media to coordinate it and make it a spectacle. This
might make them more accountable than local reps, in a weird, paradoxical
way.
	Anyway, I'm not saying that all elections in America should be
nationwide; I'm just saying that the political culture here is a little
strange. The media might be as much to blame for that as the election
method, though.