[EM] Portland specifics, and ovals for approval cutoff
Closed Limelike Curves
closed.limelike.curves at gmail.com
Thu Jul 18 14:30:21 PDT 2024
PSC is proportionality for solid coalitions
<https://en.wikipedia.org/wiki/Proportionality_for_solid_coalitions>.
On Tue, Jul 16, 2024 at 11:07 AM Richard, the VoteFair guy <
electionmethods at votefair.org> wrote:
> On 7/15/2024 3:20 PM, Closed Limelike Curves wrote:
> > Richard, I'd suggest taking a look at the newest
> > version of Wikipedia's PSC article (and the
> > citations in there); ...
>
> I don't recognize the PSC acronym.
>
> And I can't find it in Wikipedia's PSC list:
>
> https://en.wikipedia.org/wiki/PSC
>
> Also, I suggest changing the email "subject" to the full name of
> whatever PSC is.
>
> Richard Fobes
>
>
> On 7/15/2024 3:20 PM, Closed Limelike Curves wrote:
> > Richard, I'd suggest taking a look at the newest version of Wikipedia's
> > PSC article (and the citations in there); nonpartisan PR algorithms
> > other than STV are a very new field of research, and we're just barely
> > starting to study what algorithms satisfy what proportionality axioms.
> >
> > STV does try to put together a coalition, but this involves a very basic
> > greedy search for cohesive/solid coalitions that support a single group
> > of candidates. e.g. say a Hispanic Republican's preferences are
> > something like "vote for a Hispanic Republican, then non-Hispanic
> > Republicans, then a Hispanic Democrat"; whereas others Hispanic
> > Republicans care more about ethnicity than about party. In this
> > situation, there's no solid coalition for Hispanics /or/ Republicans, so
> > it's very prone to underrepresent one of these groups. IIRC the EVC's
> > proposal for a proportional STAR algorithm works on basically the same
> > principle, as does anything that assigns seats sequentially/greedily,
> > which is why I tend to dislike them; whereas PAV is optimization-based,
> > so it tends to find better apportionments across cross-cutting
> > coalitions. I think Schulze STV also satisfies similar properties (but
> > only locally, because global optimization across committees requires
> > voters to give candidates ratings).
> >
> > On Sun, Jul 14, 2024 at 10:22 AM Richard, the VoteFair guy
> > <electionmethods at votefair.org <mailto:electionmethods at votefair.org>>
> wrote:
> >
> > On 7/13/2024 5:39 PM, Closed Limelike Curves wrote:
> > > ... my guess is the effect of STV is probably going to be
> limited
> > > compared to other methods, because STV is only proportional for
> > solid
> > > coalitions, i.e. voting blocs moving in perfect lockstep with
> each
> > > other, and only if they exceed a full quota. ...
> >
> > When using STV, coalitions don't need to be "solid."
> >
> > STV calculations automatically identify de-facto "coalitions." Each
> > candidate can be thought of as a de-facto coalition.
> >
> > One way to think of this concept is that STV gives any coalition a
> > "second try" when filling the second seat, and a "third try" when
> > filling the third seat.
> >
> > In contrast, IRV provides only "one try" for a coalition to elect
> their
> > candidate. So for IRV, a "solid" coalition voting with the same
> tactic
> > does have an advantage compared to a loose (non-solid) coalition.
> >
> > I'm not saying STV is better than PAV. I'm saying this specific
> > criticism of STV -- thinking that a coalition must be "solid" -- is
> not
> > a valid reason to dismiss STV.
> >
> > Richard Fobes
> >
> >
> >
> > On 7/13/2024 5:39 PM, Closed Limelike Curves wrote:
> > > Ahh, yeah, any PR method will outperform winner-take-all on this
> > metric.
> > > If cities are using STV for their city councils, that might imply
> > > single-winner IRV actively reduces minority representation.
> > >
> > > That said, my guess is the effect of STV is probably going to be
> > limited
> > > compared to other methods, because STV is only proportional for
> > solid
> > > coalitions, i.e. voting blocs moving in perfect lockstep with each
> > > other, and only if they exceed a full quota. So, for example, if
> > ethnic
> > > minorities tend to vote for a mix of white and minority
> > candidates, or
> > > if they're split across party lines (e.g. Hispanics only go about
> > 60-40
> > > for Democrats), this will tend to break up and dilute their
> > interests.
> > > It's not enough to have a quota of Hispanics who rate Hispanic
> > > Republicans and Hispanic Democrats highly; you need to have a
> > full quota
> > > rank /either/ a Hispanic Republican or a Hispanic Democrat at the
> > top of
> > > their ballots. The effect is the same as center-squeeze, where
> > your vote
> > > gets "stuck" with a weak candidate who nevertheless has enough
> first
> > > preferences to stay in the race for several rounds. By the time
> this
> > > candidate is eliminated, the more-electable candidates with fewer
> > first
> > > preferences have been defeated.
> > >
> > > But from what I can tell, this is much trickier to resolve than
> > > center-squeeze; proportional Condorcet methods don't seem to have
> > any
> > > guarantees on how out-of-whack a coalition can get, although I
> think
> > > Schulze STV has a nice local stability property.
> > >
> > > Most ethnic minorities aren’t solid coalitions, although
> > > African-Americans happen to be so overwhelmingly Democratic they
> > might
> > > act like one. Something like PAV that approximately satisfies the
> > core
> > > property should do better at giving minority voters more
> > representation.
> > >
> > > On Thu, Jul 11, 2024 at 8:40 PM Richard, the VoteFair guy
> > > <electionmethods at votefair.org
> > <mailto:electionmethods at votefair.org>
> > <mailto:electionmethods at votefair.org
> > <mailto:electionmethods at votefair.org>>> wrote:
> > >
> > > On 7/11/2024 10:47 AM, Closed Limelike Curves wrote:
> > > > ... given there's no theoretical basis to think IRV would
> > affect
> > > > city council and mayoral seats differently. ...
> > >
> > > In the new Portland elections, "ranked choice voting" for
> > city-council
> > > seats is STV (the Single Transferable Vote) with three seats
> per
> > > district, whereas "ranked choice voting" for Portland mayor is
> > > single-winner IRV (instant-runoff voting).
> > >
> > > Of course Portland's three-seats-per-district STV city-council
> > > elections
> > > are going to yield more gender and racial diversity compared
> to
> > > single-winner IRV for electing Portland's mayor.
> > >
> > > Richard Fobes
> > >
> > >
> > > On 7/11/2024 10:47 AM, Closed Limelike Curves wrote:
> > > > I'm going to go ahead and say I'm skeptical either of these
> > > results will
> > > > replicate, given there's no theoretical basis to think IRV
> > > would affect
> > > > city council and mayoral seats differently. My guess is
> > both results
> > > > would disappear if you used a hierarchical/partial pooling
> > model to
> > > > reduce the noise in the estimates.
> > > >
> > > > On Thu, Jul 11, 2024 at 10:45 AM Michael Garman
> > > > <michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>
> > > <mailto:michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>>
> > > <mailto:michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>
> > > <mailto:michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>>>>
> > > > wrote:
> > > >
> > > > And that’s bad! But it doesn’t negate the point I
> made. In
> > > council
> > > > races it helps. And that’s good!
> > > > On Thu, Jul 11, 2024 at 1:44 PM Closed Limelike Curves
> > > > <closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>
> > > <mailto:closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>>
> > > > <mailto:closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>
> > > <mailto:closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>>>> wrote:
> > > >
> > > > > In mayoral elections, RCV seems to *decrease*
> > gender and
> > > > racial/ethnic diversity.
> > > > Sounds substantial!
> > > >
> > > > On Thu, Jul 11, 2024 at 10:28 AM Michael Garman
> > > > <michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>
> > > <mailto:michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>>
> > > > <mailto:michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>
> > > <mailto:michael.garman at rankthevote.us
> > <mailto:michael.garman at rankthevote.us>>>> wrote:
> > > >
> > > > > In city council elections, RCV has a small
> but
> > > positive
> > > > effect on racial/ethnic diversity
> > > > Sounds substantial!
> > > >
> > > > On Thu, Jul 11, 2024 at 1:26 PM Closed
> > Limelike Curves
> > > > <closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>
> > > <mailto:closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>>
> > > > <mailto:closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>
> > > <mailto:closed.limelike.curves at gmail.com
> > <mailto:closed.limelike.curves at gmail.com>>>> wrote:
> > > >
> > > > Empirically, IRV adoption has no
> substantial
> > > effects on
> > > > diversity
> > > >
> > >
> > <
> https://www.newamerica.org/political-reform/reports/rcv-impact-on-candidate-entry-and-representation/
> <
> https://www.newamerica.org/political-reform/reports/rcv-impact-on-candidate-entry-and-representation/>
> <
> https://www.newamerica.org/political-reform/reports/rcv-impact-on-candidate-entry-and-representation/
> <
> https://www.newamerica.org/political-reform/reports/rcv-impact-on-candidate-entry-and-representation/>>>.
> In theory, I'd expect a small decrease in representation for minorities,
> because people of color tend to have higher rates of spoiled ballots, so
> IRV should hit them the hardest.
> > > >
> > > > In general, the theoretical advantages of
> IRV
> > > over FPP
> > > > are outweighed by its practical costs
> (spoiled
> > > ballots,
> > > > lower trust in elections, cost, etc.).
> > > > ----
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