[EM] Portland specifics, and ovals for approval cutoff

Richard, the VoteFair guy electionmethods at votefair.org
Tue Jul 16 11:06:54 PDT 2024


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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