[EM] Unified Majority electoral system

[John]

[Not subscribed, so please CC me replies]

I'm pushing two new pieces of political science, as far as I can tell. One
is about representation structure, and the other is about elections.

On representation structure, I've been suggesting bicameral legislatures
with a single-seat (Senate) and a multi-seat (House) component.  Senates
are overall representation, while the House becomes a
proportionally-representative institution with more-individualized voices.

This all stands on an electoral system called Unified Majority.

https://www.nordicmodelusa.org/policy/government-and-representation/elections/unified-majority-elections/

Let's run through history.

The United States once primarily nominated by party caucus.  Party central
committees would select their own representatives and put them up for the
voters to elect in the general election.

The rise of the Party Primary put more control in the hands of the
electorate, allowing voters registered to the Party—party members—to
nominate directly.  Focus shifted to candidates rather than parties,
solidifying the two-plus party system.

Even so, the two parties are the Democrats and the Republicans, and
whichever gets the most votes gets their candidate out front.  Primaries
only represent the voters actually voting, and party-line voters have less
marginal utility than activist voters, so the Party Primary tends to draw
representation for a surprisingly-small minority.

Unified Majority changes this.

Unified Majority uses Single Transferable Vote in a nonpartisan blanket
primary.  For a single-winner election, it nominates five or seven; for a
multi-winner election, it nominates twice the number of ultimate winners.
If there are fewer candidates, no primary occurs.

A single-winner election completes with a Condorcet vote, notably Tideman's
Alternative Method; while multi-winner elections use STV.

Parties represent platforms, and a variation in party ideology can result
in multiple nominations from the same party under Unified Majority.  The
Condorcet single-winner represents the center of this ideological span,
thus the overall consensus.

Data suggests voters will rank six candidates fairly reliably, and then
rapidly drop off.

A single-winner ranked election between an odd number not exceeding twice
as many candidates should find the Condorcet winner.  With eleven
candidates, voters should largely rank up to the center candidate.  Fewer
candidates improves on this:  excluding bullet-voters, a five-candidate
election ensures the most-extreme voters will overlap the center by ranking
merely three candidates; for seven, it's four.

Likewise, this overlap tends to enhance STV in large fields of candidates.
A voter centered between two candidates will reach at least three
candidates to their preferred direction if ranking six.  The Nonpartisan
Blanket Primary can thus easily include six times the ultimate nominees—for
seven nominees, that's 42 candidates.

This explains the reason for a primary.

My preferred STV system is Meek-STV, although I'm uncertain how that really
compares to Warren-STV.  My experiments suggest Meek-STV will always elect
a candidate representing the Droop quota:  if electing 3 and 25% of the
population ranks some subset of candidates above all candidates ranked
first, second, and third by the other 75% of the population, then the 25%
will determine their own candidate.

I have considered a more-convoluted measure:

 - Run STV;
 - Replace the final winner with a Condorcet candidate computed from all
ballots with their final weights (including weight at exhaustion),
excluding the winning candidates.

Largely, I have problems with the early-elimination issue in STV, and have
considered tweaks like restarting the count from the top after each win,
accounting for the weights of the ballots and excluding the winning
candidates (this will work with Warren, but not Meek).

Unified Majority with Meek-STV/Tideman's Alternative has a few interesting
features:

 - It represents the span of the electorate's ideology, rather than
parties, in the General;
 - It is immune to gerrymandering;
 - It is immune to tactical nomination for MANY reasons;
 - It maximizes the likelihood of actually finding and electing the
Condorcet candidate when given a large number of candidates.

Unified Majority multi-winner is only really necessary for (n) winners with
(6n) candidates, in theory, but drawing down to (2n) makes me more
comfortable that we're not losing voters who vote for 2-3 candidates who
are ultimately losers and thus get their ballots exhausted.

Thoughts?
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