[EM] Improved Instant Pairwise Elimination

[Daniel Carrera]

On Thu, Jul 8, 2021 at 2:19 PM Susan Simmons <suzerainsimmons at outlook.com>
wrote:

>
> At each elimination step IPE eliminates the Condorcet Loser if there is
> one, otherwise it eliminates the loser of the pairwise contest with the
> most winning votes.
>
> We propose eliminating (at each elimination step among those not
> eliminated previously) the Condorcet Loser if there is one, else the
> pairwise loser between (1) the candidate whose maximum support for any of
> its pairwise wins is minimal, and (2) the loser from the pairwise contest
> with the fewest losing votes (i.e. the Gross Loser).
>
> In other words eliminate the CL when there is one, otherwise eliminate
> whichever is less preferred... the GL or the closest thing to a CL.
>
> Is this better than BRGL which simply eliminates the GL at each step?
>
> Yes and no. On the one hand it is more aggressive and thorough about
> getting rid of the least desireable remaining candidate as soon as
> possible. On the other hand it is probably a harder sell to a public
> lacking patience in these matters ... who tend to assume that the order of
> elimination of "losers" doesn't make much difference, if any.
>

I think this is a technically superior method that has zero chance of being
adopted for a government election. If the goal is to get an ideal method,
we already have them in the form of Ranked Pairs, followed by Schulze. But
think of what it would actually take to present a proposal to (say) the
city council of Burlington. Here is the text for the IRV proposal from 2019
(169 words):

-----
All elections of mayor, city councilors and school commissioners shall be
by ballot, using a system of ranked choice voting without a separate runoff
election. The chief administrative officer shall implement a ranked choice
voting protocol according to these guidelines:
 (1) The ballot shall give voters the option of ranking candidates in order
of preference.
 (2) If a candidate receives a majority (over 50 percent) of first
preferences, that candidate is elected.
 (3) If no candidate receives a majority of first preferences, an instant
runoff re-tabulation shall be performed by the presiding election officer.
The instant runoff re-tabulation shall be conducted in rounds. In each
round, each voter’s ballot shall count as a single vote for whichever
continuing candidate the voter has ranked highest. The candidate with the
fewest votes after each round shall be eliminated until only two candidates
remain, with the candidate then receiving the greatest number of votes
being elected.
 (4) The city council may adopt additional regulations consistent with this
subsection to implement these standards.
-----
Here is my best attempt to write a similar proposal for BRGL (167 words):

-----
All elections of mayor, city councilors and school commissioners shall be
by ballot, using a system of ranked choice voting without a separate runoff
election. The chief administrative officer shall implement a ranked choice
voting protocol according to these guidelines:
 (1) The ballot shall give voters the option of ranking candidates in order
of preference.
 (2) If a candidate receives a majority (over 50 percent) of first
preferences, that candidate is elected.
 (3) If no candidate receives a majority of first preferences, the
presiding officer shall conduct elimination rounds. For every pair of
candidates "A" and "B", the presiding officer shall tally the number of
votes that rank "A" higher than "B" and the number of voters that rank
candidate "B" higher than "A". Then, the presiding officer shall
successively remove the candidate with the fewest votes in any such
pairwise tally until one candidate remains, who shall then be elected.
 (4) The city council may adopt additional regulations consistent with this
subsection to implement these standards.
-----

Now think of what it would take to write your modified BRGL in this
language.

Daniel.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20210708/1632119a/attachment.html>