SODA voting (Simple Optionally-Delegated Approval): Difference between revisions
Content deleted Content added
imported>Homunq |
Psephomancy (talk | contribs) →Sample Ballot: clean up (AWB) |
||
(12 intermediate revisions by 3 users not shown) | |||
Line 7:
<table border='1px' width='80%'><tr><td>
'''Vote for as many candidates as you approve, or vote for one candidate to delegate your vote:'''<br>
'''If you only vote for one candidate, your vote is delegated to that candidate, unless you check the box below.''' A delegated vote means that, if your favorite candidate shows preferences above, he or she may use your vote to approve of one or more of the most-preferred of them. For instance, if he or she can not win, he or she might approve of some other "compromise" candidate(s) who can.<br>
''Note: If you vote for more than one candidate, or if you vote for a write-in or other candidate with no declared preferences, your vote is not delegated. In that case, no-one can add approvals to your vote, and it does not matter whether you check the box above.''
</td></tr></table>
Line 26 ⟶ 28:
|-
|valign=top|
:a) '''Before the election, all candidates must strictly rank
|-
|valign=top|
Line 43 ⟶ 45:
:b) '''Voters may approve one or more candidates, and also have the option to mark "Do not delegate". <u>Delegated votes</u> and initial <u>total approvals</u> are tallied and announced for each candidate.''' ''Announcing full tallies makes step 3 predictable and fair.''
<br>
<big>3. Candidates take turns to publicly use their delegated votes,
<br>
:a) ''(optional)'' There is a one-week period for candidates to analyze and negotiate based on these preliminary results. ''Actually, the optimal strategies for all candidates and the resulting winner will already be obvious. Usually, all candidates except this winner would concede as soon as preliminary results are announced. However, for the occasional candidate inclined to act irrationally in a way that matters - say, by not delegating to an ally, even though the alternative is to see an enemy elected - this interim period would give them a chance to rethink things and come into reason.''
Line 52 ⟶ 54:
|-
|valign=top|
:b) '''
|valign=top|
<small><u>'''Use their delegated ballots'''</u>: The process by which a candidate effectively adds approvals to the votes delegated to him or her. When, for example, candidate A uses their delegated ballots to approve of B and C, then B and C's approval totals are each increased by A's delegated vote total. When it is a candidate's turn, they may choose to approve of nobody else, for instance if they believe they will win; but this counts as using their delegated votes, and they will not be given another chance to change that decision. When all candidates have used their votes, the election is over.</small>
|-
|valign=top|
::i. If the candidate using their delegated votes has more than 5% approval, '''they may choose which candidates approve on their delegated ballots, <u>consistent with preferences</u>
|valign=top|
<small>'''<u>Consistent with preferences</u>
|-
|valign=top|
::ii. ''(optional)'' If the candidate using their delegated votes has 5% approvals or less, their delegated ballots are used to <u>automatically approve</u> their preference between the frontrunners. ''Automatic approvals respect predeclared preferences but prevent minor candidates from having discretionary kingmaker power.''
::iii. ''(optional)'' If the candidate is a write-in or got less than 1% direct approvals from voters, they may not use their delegated votes. However, any candidate may approve a write-in, regardless of the predeclared preferences. ''Write-ins do not have a chance to declare or figure in the pre-declared preferences. Candidates with less than 1% are not allowed to use delegated votes to discourage a frivolous proliferation of candidates.''
|valign=top|
<small>'''<u>Automatic approvals</u>''': When approvals are assigned automatically for candidate X, they are set to approve as many of their pre-declared preferences as possible without approving both of the two candidates with the highest current approval totals that they prefer differently. (For example, say that X's preferences were for
|-
|valign=top|
Line 73 ⟶ 74:
=== Notes on rules ===
(technical issues; moved to talk page)
== Example ==
Line 101 ⟶ 80:
{{Tenn_voting_example}}
In this simplified example, all the residents of each city agree on the rankings of all the other cities, so there would be no reason for anybody to do anything but bullet vote. Memphis has the first option to choose approvals for its delegated votes, and, as the leader, decides to approve noone but itself. Nashville goes second; it is the pairwise champion (Condorcet winner), so it also declines to approve any others.
== Advantages ==
Line 146 ⟶ 125:
Simple response to a ''politician'' who makes this argument: "You just want the only smoke-filled room to be the one inside your skull." That is, minority factions '''should''' have a seat at the table, as long as everything is done transparently. The two-party system stifles some of the valid concerns of the members of the party coalitions. In SODA, all vote totals, preference orders, and final approvals added to delegated ballots are known; in the end, that's not a smoke-filled room, it's a transparent seat at the table, with a just degree of power which is derived from the people.
=== "There are other systems which are better in some ways"? Yes, but unlike them, SODA is better than plurality in
This is true. [[Condorcet]], [[Range Voting]], and Median systems like [[Majority Approval Voting]] (or others: [[Majority Judgment]], [[MCA]], or [[Bucklin]]) each have some claim to be the "best voting system". But SODA is the best system which has no downsides versus plurality. All those other systems require more-complicated ballots. All of them require more-complicated, or even dishonest, strategic decisions from the voter, to get the most effective vote.
So in the end, while any of those other systems would be, in my opinion, a clear net benefit versus plurality, with SODA you don't need any qualifications like "'''net''' benefit" or "in my opinion". It is simply better, in every way.
Line 154 ⟶ 133:
=== "Sounds too much like a parliamentary system, which has caused problems in [Italy / Israel / wherever]"? No, SODA still leaves "buck stops here" responsibility. ===
SODA does involve some parliamentary-style negotiation for
=== "Why go to the trouble of pre-announced rankings and a second round? Why not just have candidates pre-announce the approvals they will add to their delegated votes?" Because the best compromise is only clear after the votes are tallied. ===
This sounds appealing, but would not work if two similar candidates were in a close race to see which had more first-choice votes, while an opponent stood ready to take advantage if they split the vote (that is, in the Chicken Dilemma, also discussed
In general, this system, because it provides perfect information on voting totals at the time when delegation is happening, will make strategy obvious. This has the paradoxical result that, as long as most voters agree with their favored candidate's chosen ranking order, this system will in practice be '''more Condorcet compliant than a Condorcet method''' (because strategy could confound a true Condorcet method more often than SODA).
== Criteria Compliance ==
SODA itself does not satisfy [[monotonicity]] due to a complicated and implausible scenario involving 5 or more candidates. However, a slightly-modified version in which, before the delegated assignments, candidates can self-assign a penalty to be assessed at the end of the delegated assignment round, does. This modified version, MODA, is effectively identical to SODA for any plausible real-world election.
It does not satisfy the [[independence of irrelevant alternatives]] criterion in general, but it does if the "irrelevant alternative" is assumed to delegate votes in the same way as any candidate whose delegable votes they supplant. Similarly, it can only pass the [[participation]] and [[consistency]] criteria if it is assumed that candidate delegations do not change. These assumptions are ''not'' realistic, but they do show that the method is in some sense "close to" passing these criteria.
In any case where honest delegation could show a majority Condorcet winner, such delegation forms a strong Nash equilibrium. This shows that in general, strategic refusal to delegate is likely to fail.
=== Condorcet criterion (includes highly technical discussion) ===
Line 193 ⟶ 175:
Each "undelegated approval elector" would know the statewide non-delegated approval total, and the total of number of affiliated electors throughout the EC, for each candidate. Other "approval electors" would count as fractionally affiliated based on their known approval totals. These electors would be sworn to vote for whichever of the two candidates with the most nationwide electors had the highest statewide undelegated approval total. They would be chosen by the candidate for whom they were sworn to vote.
[[Category:Single-winner voting
|