Moving to

I'm moving to Mostly.

I plan to use that site as a "self-marketing website" of sorts and to manage content in a way that I would otherwise not be able to do on blogger alone.

This blog will stay, ostensibly for more provisional ideas prior to refinement. I'll be gradually moving content (I still like) over to the other website. =)

Wednesday, March 2, 2011

Truthful Voting through Approval Voting

Noting that enthusiasm is building up for the coming General Elections, it is timely to assess our current voting system. We use a simple plurality system where each voter may choose only one candidate and the candidate with the most votes wins. In situations with more than two candidates, this system entails the possibility of voters being in a situation where they have the incentive to misrepresent their preferences.

Consider a situation where candidates A, B, and C have 40%, 35% and 25% of the electorate in support respectively. B's supporters do not mind C, but do not want A to win. C's supporters do not mind B, but also do not want A to win. In the plurality voting system, C's supporters have the incentive to misrepresent their preferences and vote for B rather than vote truthfully and have A come into power.

It can be proven mathematically that where voters' preferences are represented by a ranked order of candidates, any voting system offers situations where voters have the incentive to misrepresent their preferences. This is an unfortunate and inescapable reality. However, where voters' preferences are represented as "Approve"/"Do not approve" ratings for each candidate, a voting system known as “Approval Voting” gives voters the incentives to vote "truthfully". In Approval Voting, voters cast "Approve"/"Do not approve" votes for each and every candidate, and the candidate with the highest approval level wins.

The truthfulness of the Approval Voting system rests on the idealized "Approve"/"Do not approve" representation of preferences. I argue that elections are not popularity contests but polls of the electorate to see who has a mandate to represent them. As such, a voter might conceivably support multiple candidates or none at all. With Approval Voting, the results of the election unambiguously describe "the mandate of the people". A winner with 90% approval can be said to truly have 90% approval from the electorate as there is no incentive to misrepresent preferences. Conversely, a winner with just 20% approval can be unambiguously seen to have a weak mandate.

In addition, this ameliorates the situation for the opposition with regards to election deposits, since a viable candidate may stand and have approval from a large fraction of the electorate, yet that same large fraction may prefer another candidate.

I suggest that such a system be considered for subsequent elections. This would be a worthy matter to debate after the upcoming elections.


Aaron Hamlin said...

I think you've come to the right conclusion. I belong to a group that exhaustively studies voting theory. We have an article specific to Approval Voting you may be interested in:

I think you'll be happy to find us a great resource. And as you correctly hint at, Approval Voting does a great job at selecting the Condorcet winner. You also correctly hint at the reality that Arrow's Impossibility Theorem only applies to preferential systems. You're way ahead of the game. We'd love to have you in our group. You can look at our Facebook group for updates. You can join from our homepage, if you wish.

Great job, Jeremy.

Nina Yeoh said...

This is indeed very interesting.