Asset voting

Revision as of 15:28, 19 February 2020 by Psephomancy (talk | contribs) (format references)

Asset voting is used to refer to a voting system in which votes are considered as "assets" given to candidates. If no candidate gets more than the winning threshold (i.e., a majority, in the single winner case; generally speaking, a Droop or Hare Quota), then the candidates can redistribute "their" votes to other candidates until a winner exists. Variations exist with different constraints on transfers - for example, the candidate with the fewest votes might be forced to redistribute their votes first.

Asset voting was invented in 1874 by Lewis Caroll (Charles Dodgson), and independently reinvented and named by Forest Simmons and Warren Smith.[1][2]

If used as a multi-winner voting method, it obeys most proportionality criteria, if the requisite assumptions about coalitions are extended to include candidates as well as voters. For example, since Asset allows a negotiator or group of negotiators who hold a certain number of Droop Quotas of votes to guarantee the election of up to that number of their preferred candidates, if the negotiators follow voter preferences then proportionality for Droop solid coalitions is satisfied. In such use, it is similar to delegable proxy systems except that, unlike such systems, it has public elections only at regularly scheduled intervals (proxies are not "revocable") and elects a fixed number of representatives with equal power.

Asset always picks a winner or winner set that is in the Smith Set based on negotiators' preferences (which is not necessarily the same as the voters' preferences, since the negotiators may be corrupt, change preferences mid-negotiation, not know the voters' full preferences, etc.) if the negotiators are given enough time to negotiate, are honest with each other in their negotiating moves, and don't attempt to strategically alter their preferences,[dubious ] meaning that if the negotiators have discussed every relevant permutation of winners or winner sets, Asset will always produce an outcome that can earn more votes from the negotiators during the negotiations than any other possible outcome, unless certain outcomes earn more votes than each other in a Condorcet cycle, in which case one of those cycling outcomes will win.

Asset can, under ideal conditions in the multiwinner case, render many free-riding strategies needless; this is because, in some sense, the negotiators can do vote management themselves. Consider the example of three parties, A, B and C, where 51 voters vote for B candidates, 49 vote for A candidates, and 10 for C candidates, and there are 5 seats to be elected. Supposing every voter gives maximal support to all of the candidates of their chosen party, and no support for any other candidate, Party B will win 3 seats in most PR methods. However, if the 49 A voters divide themselves as evenly as possible between 3 of their candidates (17 of them bullet vote the first, 16 each bullet vote the second and third candidates), and a Droop quota is spent every time someone is elected in the PR method, then Party A will be able to win 3 seats instead. With Asset, the B candidates can agree to divide their 51 votes evenly between 3 of them (17 each), ensuring that their candidates will be 3 of the 5 candidates with the most votes when the negotiations end and thus win. [3]

Note however that free riding still can work if a voter honestly supports both a candidate with a small base and a candidate with the same small base combined with other bases, as the voter may wish to give their vote to the first candidate to elect them and hope the other bases will elect the second candidate, giving the voter two rather than only one of their preferred candidates. This type of free riding can lead to popular candidates losing to candidates equally preferred to them by smaller groups of voters if too many voters attempt it.

Asset Voting also has sequential and Bloc versions of itself, which are generally less proportional and more majoritarian than regular Asset in the multiwinner cases (with Bloc Asset, a majority can win every seat). All of these various forms of Asset Voting can be algorithmized, and under certain (relevant) assumptions, become some type of Condorcet or Condorcet PR method.

References

  1. "Asset voting was invented by Lewis Carroll (Charles L. Dodgson)!". RangeVoting.org. Retrieved 2019-03-02.
  2. Black, Duncan (May 1969). "Lewis Carroll and the Theory of Games" (PDF). The American Economic Review. 59 (2): 206–210.
  3. "Different reweighting for RRV and the concept of Vote Unitarity". The Center for Election Science. 2019-06-29. Retrieved 2020-02-19.