[EM] IRV counting with integers to handle multiple candidates at the same preference level

[Richard, the VoteFair guy]

I'd like to stop the misconception that IRV -- instant runoff voting, 
also called "single-winner ranked choice voting" -- cannot allow a voter 
to mark two or more candidates at the same preference level.

In particular, it's ridiculous that the FairVote organization promotes 
the practice of tossing out a ballot when the counting reaches a 
preference level where the voter has marked more than one candidate.

Although such shared preference levels are easy to handle using 
fractions or decimals, that violates the common legal requirement that 
votes be allocated to candidates in "whole" numbers.

Instead it can be done using only integers.  It just involves 
"grouping."  Here's how:

When there are two ballots that rank candidates A and B at the same 
preference level, one of the ballots is allocated to candidate A, and 
the other ballot is allocated to candidate B.

When a third ballot with this preference is encountered, it's not yet 
allocated.  Then when the fourth arrives the third and fourth ballots 
(with this pattern) are allocated to the two candidates, with one ballot 
going to each candidate.

When there are 379 ballots with this pattern, 378 will be allocated, and 
only one ballot will be uncounted.  That's much better than tossing out 
all 379 ballots.

It's that simple.

Writing the software is not difficult.  It just involves grouping 
equivalent ballots together.  This grouping must be done separately for 
each elimination round because the patterns change as candidates are 
eliminated.

If anyone wants to know how the software can do this using only 
integers, and simple C-language-like statements, just ask.  I've 
implemented it in my vote-counting software on GitHub.

The importance of this issue goes beyond a voter not having a preference 
between two (or more) candidates.

Most of us voters want to be able to mark a strongly disliked candidate 
at the lowest preference level.  For example, imagine having 9 
candidates and 6 ranking levels and strongly disliking candidate "I":

A > B > C+D > E > F+G+H > I

Not being able to rank candidate "I" at the lowest preference level is 
unacceptable!  Yet that can't be done if IRV counting can't handle 
shared preference levels.

(And having 9 preference levels for 9 candidates puts us on a slippery 
slope to how to handle the 135 candidates in the infamous California 
gubernatorial recall election.)

Keep in mind that the number of viable candidates in elections will 
increase.  That's because vote splitting in general elections is what 
caused political parties to limit themselves to just one nominee from 
each party.  As more places adopt IRV and other better ranked-choice 
methods, vote splitting won't be an issue.

There's yet another reason some political parties will need to offer a 
second candidate.  It defeats the election tactic named "blocking." 
That's the tactic of giving money to support a weaker candidate in a 
primary election so that it's easier to defeat that party during the 
general election.  A clear example happened in the 2008 U.S. 
presidential election when Hillary Clinton was blocked from reaching the 
general election partially because some Republicans gave money to Barack 
Obama based on their expectation that he could not possibly win the 
general election.

Another reason for political parties offering a second nominee is that 
in a gerrymandered district (which applies to most U.S. federal and 
state districts) the winner's party is pre-determined, so offering just 
one nominee means the district's minority-party voters have no 
meaningful choice in the general election.

(By the way, as pointed out in a recent article at the Center for 
Election Science, this is why extremist candidates are getting elected 
rather easily under our single-nominee election system.  They can get 
elected with plurality support from less than half the dominant-party 
voters, who themselves only need to be around 55 or 60 percent of the 
district's voters.  The single-nominee rule means the extremist 
candidate is virtually unopposed in the general election.)

(Of course defeating these tactics won't come from political parties, 
and certainly won't come from government initiatives.  Yet ways to 
defeat these unfair political-manipulation tactics are waiting to be 
adopted.)

(BTW, tiny parties, with fewer than, say 15 percent of the voters 
registered in that party, would only get one nominee.  Or they would be 
allowed a second nominee when a big party fails to offer a second nominee.)

So, the increase in the number of party nominees, and hopefully an 
increase in opposition parties, will increase the number of candidates. 
This means the places that get stuck with IRV (in spite of much better 
methods), should not also be stuck with ranking each candidate at a 
different preference level.

Of course the FairVote organization avoids this fairer approach because 
they're trying to use IRV as a stepping-stone to STV, and STV becomes 
complex when voters mark ballots this way.  But it's time to reject the 
unfairness of tossing out IRV ballots just because counting those 
ballots under STV would become complex.

(Also, there are better STV-like methods that don't have the limitations 
of STV.)

Now that discussions of IRV are increasing because of the proposed 
"Forward Party" endorsing "ranked choice voting," those of us who 
understand the math behind vote counting need to make it clear that IRV 
does not have the shared-ranking limitation that FairVote imposes in 
their certified software.

Probably all of you who write messages on this forum already understand 
this concept.

Yet I'm hoping that those who only read this forum's messages will 
understand that FairVote's claims (on their website and elsewhere) that 
IRV ("single-winner RCV") cannot handle a voter marking more than one 
candidate at the same preference level is a request to drink their 
Kool-Aid, not an actual limitation in IRV.

Richard Fobes
The VoteFair guy