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There are two main families of voting systems in the world: proportional and plurality/majoritiarian.

The latter category is commonly referred to as "winner-take-all" and designed to manufacture a single-party majority government.

With winner-take-all voting in each riding there are winners -- voters who were able to elect a representative -- and losers -- voters who elected no one. There were over nine million losers, or 52 per cent, in the last federal election.

The results of this winner-take-all system do not reflect how many people support each party, and can therefore be quite distorted. For example, handing a single party with 39 per cent of the vote the majority of seats and 100 per cent of the power.

This is Canada's current electoral system and in the last two elections have garnered the country two majority governments that don't have a majority of the vote.

Proportional representation (PR), on the other hand, is the simple principle that parliaments should reflect how people vote are are designed so each voter can help elect an MP who shares his or her values.

For example, if a party receives 30 per cent of the vote, it would receive roughly 30 per cent of the seats.

The key to any PR system is multi-member districts or regions.

Evidence strongly suggests that proportional systems not only lead to fair results, but are correlated with stronger government performance, better reflecting the wishes of citizens, on a range of important issues.

There are two main proportional systems that could work for Canada: Single Transferable Vote (STV) and Mixed-Member Proportional (MMP).

Each system delivers on important values like voter equality, effective votes, regional balance, diversity and collaborative politics.

We've compiled some basic information on the difference between STV and MMP to help inform you about what you need to know about PR in Canada.

Mixed-Member Proportional uses a two-vote system

MMP includes two votes on the ballot:

1. A vote for a single local MP to represent your riding decided by a first-past-the-post election -- exactly like you vote now.

2. A second vote is for a preferred party's regional candidates. This is sometimes called "the top-up vote."

In the model suggested by the Law Commission of Canada, almost two thirds of the seats are elected this by the first vote.

With the top-up vote, you can vote for just the party, or you can vote for a specific candidate. The ability to vote for specific candidates if you wish is called an "open list." About one third of the seats are elected this way.

Voters may vote for a candidate from one party for the local seat and a candidate from a different party for the regional vote.

The percentage of support each party receives on the "top-up" portion of the ballot determines what percentage of seats it should have in that region.

If a party didn't win enough local ridings in relation to how many votes they received in a region, voters for that party will be able to use top-up votes to elect regional MPs until the overall results are proportional to the vote share.

They are designed to correct the distortions of first-past-the-post and make (almost) every vote count.

Versions of MMP are used in eight countries including Germany, Scotland, New Zealand, and Wales.

MMP was recommended by the Law Commission of Canada (2004) and several provincial assemblies/committees.

Extra details: MMP and proportional results

MMP can be designed to be more or less proportional by varying the number of top-up seats available or the size of the regions they are elected from.

In the most proportional MMP model proposed for Canada, the regions would each elect 12-14 members (this would not be possible in all parts of Canada), meaning that the effective threshold (i.e., minimum percentage of top-up votes needed) for a party to earn a seat in those regions is about seven-eight per cent of the vote.

Some models (and past provincial committees) have proposed smaller standard regions, such as eight ember regions (5 top-up seats and 5 local seats), making the regional MPs more local, and the threshold to get a seat about 12 per cent. This still delivers good proportionality but makes it harder for smaller parties such as the Greens to win seats outside of areas where they are strongest.

The single member local seats with MMP can also be elected using a winner-take-all preferential ballot instead of first-past-the-post: See a video of this model, which Fair Vote Canada calls "Jenkins MMP" after the UK Jenkins Commission which recommended something very similar, here (identified on the simulation graphic as MMP-8)

Based on our current parties and how people voted in 2015, MMP would deliver strongly proportional results.

Single Transferable Vote relies on ranking candidates

STV is a proportional system in which voters rank their candidates to elect a team of local MPs.

For example, five single member ridings, which now each elect one MP using first-past-the-post, could be combined into a local district electing five MPs.

Voters rank their choices, as few or as many as they wish. They can choose from candidates of the same party and rank candidates across party lines.

STV gives voters maximum choice. It allows voters to vote primarily by party affiliation or by the individual characteristics of the candidates -- whatever is most important to them.

Elections Canada may count the ballots like a multi-member run-off vote. The candidate with the fewest first choice votes is eliminated and those ballots are transferred according to the second choices of those voters.

Repeat until you have five candidates left, who become the local MPs.

It is interesting to note that many countries count the STV ballots with an additional two steps. This is the counting method used in Ireland and recommended by the BC Citizens' Assembly. A study of 300 seats showed the outcome is identical to the simpler counting method 97 per cent of the time. The method with the additional steps is described on this page. Take a look for more info.

With STV, instead of one party sweeping a whole area, the results are proportional and reflect the diversity of opinion in the district.

STV or SNTV (a variation) is used in six countries, including Ireland and Malta. It is also used in one Australian State, one Australian Territory, and the Australian Senate (Australia's lower house uses winner-take-all Alternative Vote). STV was used in the cities in the Western provinces of Canada for 30 years. It was removed because it worked exactly as intended -- giving fair seats to the opposition parties.

STV was recommended by the B.C. Citizens' Assembly and received 58 per cent of the vote in the 2005 referendum.

Extra details: STV and STV+

Like MMP, STV can be designed to be more or less proportional.

In a five seat local district, a candidate would need about 16 per cent of the vote to win a seat, but the last candidate elected could get elected with as low as 12 per cent.

In large urban areas where the population is packed together, districts could easily elect more than five MPs, making the results there even more proportional. This was done when STV was used in Winnipeg.

In the rural areas, districts would be smaller -- electing two or three MPs -- making them less proportional to accommodate our geography. With any PR system for Canada, there might be some exceptional places such as Labrador that just keep a single member.

With an average district size of four MPs, STV provides very good overall proportionality, but is more difficult for the Greens or other national parties whose support is weak to win seats in particular regions.

For example, the Green Party in Ireland, which uses STV, received just 2.7 per cent of the vote in the last election but won two seats -- a fully proportional result would have been four.

To achieve even more proportionality with STV, an option is STV+.

STV+ works by borrowing an idea from MMP -- adding a layer of "top-up" MPs in each region. Because STV is already a very proportional voting system, there is not much to fix. About 14 per cent regional top-up MPs would give very strong proportionality.

STV+ would allow voters for small parties who live where the party is not strong, or voters for parties which are very weak in particular regions -- to elect MPs in most places in Canada.

Have a few question about MMP? No sweat! Read more here.

Still have question about STV? Learn more about STV here.

Interested in contributing to this series on proportional representation? Send us a pitch to [email protected] with the title "Proportional representation series"

Part 1: Proportional representation is not 'too complicated' -- the fix is in

Part 2: Activists gear up for 'historic opportunity' to usher in proportional representation

Part 3: Proportional representation for Canada: A primer



Part 4: Nation-to-nation recognition, not electoral reform, key to increasing Indigenous voter turnout

Correction: Some models proposed smaller standard regions, such as eight ember regions (5 top-up seats and 5 local seats).

Anita Nickerson is a coordinator with Fair Vote Canada.

Antony Hodgson is president of Fair Voting B.C.