The objective of a voting system, at least for this election, is to measure the mandate of the people. While First-Past-the-Post has been widely used in Singapore and elsewhere, it does not make sense in this setting. This is because an individual may support more than one of the candidates to be President. This would certainly be likely in a situation where all candidates have been screened for suitability. As such, first-past-the-post is the wrong tool for measuring the mandate of the people.
Enter Approval Voting. (Which I've written about previously.  ) Approval Voting is a system where voters indicate all the candidates that they would support for a position. That is to say each candidate is rated with either "Approve" or "Do Not Approve". The candidate with the highest number of approvals wins the election. Based on this description alone, one might conclude that Approval Voting:
- (i) is straightforward and comprehensible,
(ii) is simple to implement given our present electoral practices,
(iii) removes (or at least greatly reduces) personal dilemmas of choosing between two or more favored candidates, and
(iv) directly measures mandate of people.
Approval Voting is a good voting system and should receive consideration for subsequent elections. In parliamentary elections, it would mean that multiple opposition parties will be able to contest in a constituency without fear of splitting the opposition vote. But foremost should be the fact that Approval Voting directly measures the mandate of the people.
Approval Voting is already in used by bodies such as the Mathematical Association of America and the Institute for Operations Research and the Management Sciences. In the selection of the Secretary-General of the United Nations, rounds of preliminary approval polling are used to build consensus before a formal vote is held in the Security Council.
As such, there is a strong argument for exploring Approval Voting for use in future elections. More generally, it makes sense to form a committee to re-examine our voting system and make a recommendation on whether or not it should be changed, and if so, to what system. Such a committee might contain senior public servants, representatives from major political parties and academics who are familiar with the properties of various voting systems.
Annex on the "Truthfulness" of Approval Voting:
Specifically, the model of preferences referred to is one where individuals either support or do not support each candidate. Each candidate in the "Approved" category are equally supported, and all candidates that are in the "Not Approved" category are equally un-supported. This is known in the literature as "dichotomous preferences". This is a realistic model of the "voter thinks candidate is suitable for position" and "voter thinks candidate is not suitable for position" dichotomy.
What I mean by "misrepresenting preferences" is best illustrated by an example from the USA. In the 2000 US Presidential Elections (using First-Past-the-Post), the front-runners were Al Gore (Democratic Party), George Bush (Republican Party) and Ralph Nader (Green Party). The final outcome was that Nader got 2.74% of the popular vote and Bush (47.87% of the popular vote) won by a razor thin margin only through the electoral college versus Gore's 48.38% of the popular vote (yes, Gore had more votes). If one were a Green Party supporter, one would typically favor the Democrat platform far over the Republican platform. Thus though one would prefer Nader to Gore to Bush in that order, since the election results in just one winner, it would be strategically sensible to vote Gore even though one preferred Nader. Such misrepresentations of preferences, which can occur in first-past-the-post elections with more than two candidates, represents a distortion in the electoral poll which may have unpredictable results.
While the assumed model of preferences which generates "truthful voting" is wrong, as all models are (to any given voter, not all Tans are equal), approve/do not approve is a reasonable approximation. At the very worst, when inter-candidate preference effects are strong in the extreme, Approval Voting produces exactly the same result as First-Past-the-Post, with each voter approving only their most preferred candidate.
As a matter of personal preference, I believe it is sensible to encourage "truthful", "non-strategic voting" among voters. This is very much akin to asking someone to talk straight and direct.