[EM] Two round methods

[Rob Lanphier]

Hi Kevin!

As I'm sure you remember, I've been trying to figure out a system that
could replace California's "top-two primary" for a while.  Your
proposal could work, but I'm curious about the value it provides over
other approaches.

More inline...

On Fri, Sep 24, 2021 at 5:59 PM Kevin Venzke <stepjak at yahoo.fr> wrote:
> I see a need for non-eliminative two-round methods. I like the idea that the first round places
> a "default winner" or "guy to beat" in the electorate's consciousness, so that, possibly, voters
> would consider offering more of their preferences in the second round.
>
> A difficult thing is to make sure it is worthwhile to seriously compete in the first round, and
> also, relatedly, that the second round should not simply reverse the outcome of the first round
> based on small changes in participation rate.

It seems this is the reason for eliminating candidates in the first
round.  If one is going to have approval voting in both rounds, then
requiring a modest approval (e.g. 30% approval) to advance from the
first round to the second round would be ample motivation, even if
several candidates are allowed to advance.  I'm still fond of only
allowing two candidates to advance, so that there's a clear choice
presented to the voters in the second round.

> Here's an idea based on two-round Approval. Let's call it NETRA.
>
> 1. If the first round winner ("FRW") has majority approval, he is elected. End.
> 2. Otherwise hold the second round with all the same candidates. If this new winner has
> majority approval *and* the FRW does *not* have majority approval, then the new winner is
> elected. Otherwise the FRW wins.

I guess I'm too used to the American primary-election/general-election
split, so I'm wondering what the value is for allowing a candidate to
win with a simple majority in the first round.  It seems like a super
majority (e.g. 60% or higher) should be required to short-circuit a
second-round standoff with the first-round runner up.   Otherwise, it
seems likely to imagine something similar to following scenario with
1,000,000 votes:

A (incumbent) - 500,001 approvals
B (serious challenger) - 499,995 approvals
C (joke challenger) - 10 approvals

That's 6 voters in a 1,000,000 vote election who decide B doesn't get
a head-to-head standoff with A because perhaps some of them got
distracted by C's messaging.  Moreover, since this is approval voting
we're talking about here, it's also possible for this outcome in a
1,000,000 ballot first-round election:

A (incumbent) - 500,100 approvals
B (serious challenger) - 500,050 approvals
C (joke challenger) - 10 approvals

Now, both A and B have slim majorities for their respective approval
ratings.  Perhaps people approved "A" and "B" because "C" seemed like
a real lunatic, and "A" chose to legitimize "C" and ignore "B", and
scaremonger people who would have voted exclusively for "B" into
voting for "A" as well.

It seems to me that it shouldn't be too hard to get candidates and
voters to take the first round seriously.  A small enough
supermajority (e.g. 60%) would seem achievable for a competent
incumbent -- which would cause the rest of the field of candidates to
motivate their base to go to the polls if one candidate getting a
supermajority means  "no second round".

It also seems to me that perhaps the "short-circuit" threshold should
be a large margin (e.g. a 10% lead over the next candidate) rather
than an absolute value (like a 60% supermajority approval).  If two
candidates get over 50% approval in the primary election, it seems
like BOTH candidates should advance to the general election regardless
of the margin, since (by definition) there's a contingent who felt
that both candidates would be acceptable, but (to quote Sean Connery
in Highlander) "there can be only one".  .  If three candidates get
over 50% approval ... well, it sucks to be third place in a primary
where the rules state "only two shall advance".  What seems most
likely in a crowded first round is that no candidates get a majority

Now to reply to your other points:

> So in the second round the FRW is given a couple of perks. If he raises his vote to a majority,
> or if (again) no one can get a majority, he doesn't have to beat anyone. He can prevail based
> on his first victory.
>
> This has two purposes: It should be desirable to be the FRW. And the FRW's advantage
> should increase the electorate's assessment of the FRW's odds, so that hopefully the second
> round serves to tell us whether there is a candidate preferred by the voters to the FRW. (It
> is an approval ballot in form, but what I'm actually after is the FRW's pairwise contests.)
>
> Main concerns:
> 1. If candidates were to conclude that being the FRW is overall a bad situation. I'm not
> sure how likely this is, given that a first-round majority is an auto-win.

This seems like an unlikely strategy.  In an approval election, there
seems to be very little strategic reason to not try to get first
place, even if a majority first-place doesn't seem likely.

> 2. It's still quite possible that a majority opposing the FRW in the second round would fail
> to agree to get behind any single candidate. Then a lack of an approval majority in the first
> round would simply be repeated in the second, for no benefit. (There is, I suppose, the
> additional confirmation, for all to see, that there is no majority willing to unite against the
> FRW... It also confirms that the winner couldn't attract a majority.)

I think this is the benefit right here.  A tepid response in the
second round would be embarrassing for the FRW, and make it incredibly
difficult to claim a "mandate" on radical policy changes.  It would
also send a message to the opposition that they need to unite in order
to win.  Borrowing an old bit from the Monty Python movie "Life of
Brian", the Judean People's Front and the People's Front of Judea need
to unite against the Romans (so to speak):
<https://youtu.be/WboggjN_G-4>

Regardess, it's food for thought.  More to think about...

Rob