[EM] Sainte-Lague vs d'Hondt for party list PR

Michael Ossipoff email9648742 at gmail.com
Thu Jul 12 16:24:59 PDT 2012


You said:

> Btw, this strategy is much less risky when we talk about splitting
> districts, since the population of districts is very stable when compared to
> possible risky changes in party support.

I don't know if U.S. states are allowed to split. Are Finnish PR
districts allowed to split?

But remember that, in order for that strategy to really gain anything,
they'd have to split to, say, a size that barely rounds up to 1 seat.
They'd become single-member districts. Or 2-member districts at the
most. I just can't believe that California would split into about 53
states, even if allowed to, for apportionment advantage. Each new
state, then, would be the population-size of barely over half of a
House of Representatives district.

Note that during the years during which we used Webster, California
didn't split into lots of HR-district-size states.

> But what if it isn't the result of splitting strategy? What if those are the
> natural spontaneous parties and their vote totals? Does the result look
> wrong? It isn't wrong. SL, by doing what it does, is minimizing the
> deviation of each party's s/q from the ideal equal s/q value.
> It might _look_ wrong at first glance, because it "violates quote", but it
> isn't wrong,in terms of fair s/q.
> Yes, some people might look at the s/q values

Some people?   But not you. :-)

Remember, I tried to agree to disagree about whether people have a
right to equal representation. You refused to disagree about that. You
said that you agree that people have a right to equal representation.

Equal representation means the same representation for everyone. The
same representation for everyone means the same representation per
person. The same representation per person means equal s/q.

So, do you or do you not agree that people have a right to equal

If you do, then I have good news for you: Sainte-Lague/Webster puts
each party's or district's s/q as close as possible to the ideal equal

You said:

>, but I'd expect someone to
> notice also the unfair use of the quotas / votes.

What unfair use of the quotas/votes? Are your referring to splitting
strategy in SL? I addressed that. I said that, if there turned out to
be a splitting strategy, and if it remained even when SL's 1st
denominator is raised from 1 to 2, then Largest Remainder would be the

If you aren't referring to splitting strategy, then what are you referring to.

>> . In the S1+N seats case the large party gets 43.48% of the seats with 61%
>> of the votes. Or in other words, all 20 seats with only 12.2 quotas (7.8
>> extra seats), or only 20 seats with 28.06 quotas (8.06 seats too little).
> [endquote]
> That's ok if the parties are genuine, natural and not the result of
> splitting strategy. As I described above.
> I'm afraid some people might get upset if they think they were entitled to 8
> seats more but will get none

Undoubtedly. But thinking that they're entitled to 8 seats, and being
entitled to 8 seats aren't quite the same thing.

, and will lose a very clear (28 seats vs. 18
> seats) majority. There are thus many approaches to measuring the fairness of
> the results, and the quota based approach may be a very natural one to check
> first.

You're espousing a fairness-measure that is different from equal
representation for all, one that is in conflict with equal
representation for all.

You speak of "the quota-based approach", as if you think that the Hare
quota is the only divisor to use, or has some privileged status among
divisors. Dividing the parties' votes by the same divisor, any common
divisor, and rounding off the quotients to the nearest whole number,
will put the parties s/q as close as possible to the ideal equal s/q.
If you use the Hare quota as the divisor, for that procedure, you'll
often get a total number of seats different from the desired
house-size. So you use a different divisor. Don't be wedded to the
Hare quota.

If we allow a variable house size, then we could say: Divide each
party's votes by the Hare quota (based on some most preferred
house-size), and round off the quotients to the nearest whole number.
That rounded off quotient is the number of seats to assign to each
party. That would be a fine method.

But the fact that that divisor is a "Hare quota" based on some
preferred (but not required) house-size doesn't make it special or
privileged. How can you think that is somehow fairer to use that
divisor instead of some other divisor?

Mike Ossipoff

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