The October 19th 2015 election, with a large part of the electorate relying on strategic voting to achieve what they wanted their vote to achieve, was a dramatic demonstration of the advantage of preferential voting.
In this election, for a lot of voters the focus was squarely on what they could do to influence their own local race, not on party loyalty. In various three way races between different sets of three parties across the country, many voters were less concerned with ensuring that their first choice candidate did well, instead wishing either their first or second choice to be successful.
In few elections has the widely reported country-wide addition of first-choice votes for candidates from the same party been so meaningless: large numbers of voters were quite happy to mark the circle for the candidate of a party that might not have been their first choice a few weeks earlier, and were content that this would result in a different outcome than if their vote had instead been given to a party and pooled across ridings. Proportionality was not among their objectives this time.
It is unfortunate that our current voting system never even asks the voter what their second choice would be. It is unfortunate that it is possible to become a representative of a riding without building a consensus of half the voters. It is unfortunate that vote-splitting strategies still work to get an unpopular candidate elected.
The next government has committed to changing the electoral system. Preferential Voting allows voters to state their second choice if their first choice does not have enough support. It avoids the need for unpredictable strategic voting. It does not rely on voters having access to accurate riding-level polls in order to decide how to vote. PV changes the system, not to elect MPs who have a smaller proportion of the support of those they represent, but to make them seek a larger proportion. Being forced to only consider your first choice does not adequately express how you want to be governed. If you think your second choice also matters and want your MP to obtain more a consensus of the majority, tell your MP you want the next election to use a Preferential Voting ballot.