Kathy Dopp wrote:
Thanks Kristofer. I ignored the "all* in "all others".
I must say then, I simply do not like the Droop quota as a criteria
because it elects less popular candidates favored by fewer voters
overall and eliminates the Condorcet winners some times. The Droop
quota seems to go hand in hand with IRV and STV methods.
Then the question you should ask is where you want to balance
proportionality and majoritarianism. When dealing with multiwinner
elections, there are two objectives that work against each other. On the
one hand, you'd want proportionality, so that variation in the
electorate is reflected by variation in the assembly or council. That
is, you'd like it to have members that some people like a lot. On the
other, you'd want quality across the board, i.e. candidates that every
voter can like to some extent.
This, as my simulations show, gives a tradeoff scale (on the Pareto
frontier). At one end, the only thing that matters is that
proportionality is accurately reproduced (consider an assembly that's
elected by lot, and that it's large enough to be representative). At the
other, the only thing that matters is what the electorate as a whole
thinks of the council (which would give a majority party, even a 51%
one, every single seat; or even a well-liked minority party every single
seat, Range style).
The Droop criterion pulls in the direction of proportionality. Like the
mutual majority criterion says that a majority can control the single
outcome in a singlewinner method, the Droop proportionality criterion
says that, if you consider each seat to have a "majority", each
"majority" (Droop fraction) should be able to control the winner of that
seat. In doing so, it can go against the wishes of a larger group: it
satisfies a proportion of the electorate to a greater extent at the cost
of satisfying the whole electorate less on average.
(As someone who thinks proportional representation is important, I think
the people may actually get a better result, on the whole, by PR.
However, that kind of additional benefit arises from the dynamics, such
as minor parties or independents checking major parties. That is quite
hard to model, so when I mentioned "satisfying the whole electorate"
above, I was referring to "according to the preferences the voters gave
in the election".)
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