Voting Systems
First-Past-the-Post
The current system used in Canada is called the first-past-the-post. Voters place an X by the candidate of their choice. The candidate with the most votes wins. While this may seem to be simple, it is difficult to use as it encourages strategic voting. While a lot of people may vote naively, just putting an X by their preferred candidate, many people manipulate the system by trying to ensure their vote will not be wasted. If you are not taking advantage of the way the system works, your vote may be effectively taken away by those who are.
The main problem with first-part-the-post is vote splitting. Similar candidates or parties take votes away from each other, allowing another party to exploit this difference. It means that similar parties have to be mortal enemies of each other. Suppose there are 3 parties: A, B and C. Suppose A and B are similar so 60% of the electorate prefer A or B to C, and 40% prefer C. If A and B split the vote, getting 30% each, party C would win. If party B were to drop out, A would win. Parties A and B are thus pitted against each other, and have to try to take votes from each other. Thus the system makes enemies of people who should not be enemies.
Preferential Voting
Preferential voting is an alternative system which can be used for single-member ridings or multiple member ridings. Let's describe it for single-member ridings. This is like the system that the political parties use for electing a leader, but the voters declare their preferences ahead of time. Instead of placing an X by a single candidate, a voter orders the candidates, 1, 2, 3, etc. If a candidate has over 50% of the votes, that candidate wins. Otherwise the lowest candidate is eliminated, and the next preference of the people who voted for that candidate are used. Thus, each voter's preference over the non-eliminated candidates is always used. Eliminating the bottom candidate continues until some candidate has over 50% of the remaining votes. While this may seem more complicated, it is easier to vote, as the voter does not have to do complicated strategic reasoning. This chooses a candidate most voters approve of. It is not much more difficult to count or to explain the results.
Vote splitting does not occur in preferential voting. In the example above, whichever of A and B gets the lowest vote would be eliminated, and the other would get their votes. A and B, instead of being enemies would want to court each other to get their second preferences. Similar parties, instead of being forced to fight each other are encouraged to cooperate.
Strategic voting, as advocated at VoteStrategically.ca, is meant to simulate preferential voting. As the way the votes are currently counted in our first-past-the-post system does not optimally choose who we have to vote between, we have to guess based on polls.
Proportional Representation
Another method that has been advocated is proportional representation. This is where there are multiple members in each riding, and the number of representatives elected for each party are determined by their percentage of the vote. Whether there are multiple members or not, is orthogonal to the distinction between first-past-the-post and preferential voting. First-past-the-post and preferential voting can both be used for multi-member ridings. Both the counting and the explaining the results is more complicated for multi-member ridings.
See Fair Vote for a grassroots campaign to change the system.