[EM] What is the name of this simplest STV multi-winner method?

Bob Richard [lists] lists001 at robertjrichard.com
Fri Nov 25 15:50:51 PST 2022


"Bloc IRV" or "block preferential voting" refers to something different 
from (and even worse than) bottoms-up. You run a single-winner IRV 
count, exclude the winner from all ballots, then rerun the count to fill 
the second seat. Repeat until you have filled all the seats.  This is 
actually in use for some local elections in Utah. If your goal is for a 
sufficiently cohesive group to win all the seats, this can be even more 
majoritarian than ordinary plurality-at-large.

--Bob Richard

------ Original Message ------
>From "Kristofer Munsterhjelm" <km_elmet at t-online.de>
To "Andy Dienes" <andydienes at gmail.com>; "robert bristow-johnson" 
<rbj at audioimagination.com>
Cc "EM" <election-methods at lists.electorama.com>
Date 11/25/2022 3:32:23 PM
Subject Re: [EM] What is the name of this simplest STV multi-winner 
method?

>On 11/25/22 23:47, Andy Dienes wrote:
>>Bottoms-up IRV. It is not very proportional though.
>
>I've also heard it referred to as "at-large IRV" (LWV Boulder, https://downloads.regulations.gov/EAC-2020-0002-0003/attachment_1.pdf page 4) or "bloc IRV" (Jameson Quinn, https://twitter.com/bettercount_us/status/1412445147015622664)
>
>I wouldn't call it STV either, and it can be near-arbitrarily disproportional, e.g.
>
>1048576: A>B>C>D>E
>       1: F
>
>Two to be elected, the Droop proportionality criterion says that A and B must be elected, but B, C, D, and E are eliminated by plain IRV because they have no first preferences, leading A and F to be elected.
>
>-km
>----
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