An illustrated introduction to how proportional representation voting systems work (from Fair Voting BC). After you've watched this slide show, we suggest you check out our companion slideshow showing a more specific example of how proportional voting might work in Canada (in particular, on the Island of Montreal).

1. Understanding
Proportional Representation

2. Neighbours Have Different Perspectives
Imagine we have a region with 100,000 voters (each figure above represents 1000
voters). In each area, people live beside others with different political perspectives. In
this example, we have 40% Red voters, 30% Blue voters, 20% Orange voters, and 10%
Green voters.

3. Our Current System Uses Single Member Districts
Let’s imagine that we’re trying to elect 10 Members of Parliament. With our current voting
system, known colloquially as First Past the Post and technically as Single Member Plurality,
we divide the voters into ten electoral districts (called ridings). Within each riding, the
candidate who receives the most votes wins the seat.

4. Results With Single Member Districts
Due to how voters are distributed, candidates from the Red Party win 6 of the 10 seats.
Candidates from the Blue and Orange Parties win 3 and 1 seat, respectively. No
candidate from the Green Party wins a seat.

5. Only Half the Voters Vote for Their MP
With this kind of voting, only some of the voters end up voting for the MP elected in their
district (in this example, only 48%).

6. Very Few Voters Actually Affect the Results
In each riding, some votes are considered ‘surplus’ – that is, they’re more than were
needed to decide who won. The outcome would have been the same even if these voters
hadn’t turned out to vote. These extra voters are shown as faded figures above. Only 28%
of the voters were actually needed to determine the outcome of the election.

7. Over Half the Voters are Unrepresented
52% of the voters would not have voted for their elected MP and so will not have their
political perspective represented in Parliament. Interestingly, voters from all political
perspectives find themselves in this situation, though the proportions of such voters are
higher if they hold minority perspectives (e.g., Orange and Green Party supporters).

8. Fixing These Problems: Use Multi-Member Districts
An alternative way of electing MPs would be to remove the internal geographic boundaries
and let voters elect a team of MPs to represent this region by allowing them freedom and
flexibility to allocate their ballot to candidates who more closely align with their political
perspectives. If candidates win seats in proportion to how many voters vote for them, we
call such a system “proportional representation”.

9. Voters Can Define Their Own Communities of Interest
By allowing voters to define their own communities of interest by giving them freedom to aggregate their ballots, voters will be able to
concentrate their votes on their preferred candidates. This leads to almost no voters who haven’t voted for an elected MP. Of course,
in reality, things wouldn’t work as perfectly as shown here – there might be 38% Red Party supporters, who would be slightly over-
represented with 4 MPs, or 33% Blue Party supporters, who would be slightly under-represented with 3 MPs, or 4% Purple Party
supporters, who would have elected no MP, but in practice 90% of voters or more under proportional representation systems will help
elect an MP.

10. The Main Types of Proportional Representation
The way of electing MPs we have just described (i.e., electing a ‘team’ of MPs from a given region) is used in two of the three main
forms of proportional representation: the Single Transferable Vote (used in Ireland, Malta and a number of Australian states, amongst
other places) and List Proportional Representation (used in many countries, particularly the Scandinavian countries). These two main
kinds of proportional representation voting systems differ primarily in the ballot they use, but the resulting form of representation is
essentially identical. It is important to note that, even though we are using colours to indicate political affiliations, the voting systems
themselves need not explicitly rely on the notion of parties. STV, for example, operates solely on the basis of preferences given by
voters to individual candidates.

11. The 3rd Type: Mixed Member Proportional
The third main type of proportional representation is known as Mixed Member Proportional (or MMP), and is used in New Zealand and
Germany, as well as in the devolved assemblies of Scotland and Wales. In contrast to STV and List PR, both of which are considered ‘single
tier’ systems because all MPs are elected in the same way, MMP is a two-tier method - ie, it uses a ‘mix’ of approaches in which roughly
half the MPs (typically 50-65%) are elected using First Past the Post, and the other half using compensatory List PR (‘compensatory’ means
that MPs are elected on the list side to balance out any inequities that arise on the single member side). In this example, 5 MPs are first
elected in single member ridings that are twice as large as those used in our SMP example. As with First Past the Post, candidates from
the largest parties tend to win these riding contests.
SingleMemberSide
ListSide

12. The List Side of MMP
To determine who wins the remaining 5 seats, we look at the overall share of the vote going to candidates from the various parties.
Since candidates from the Red Party received 40% of the vote, a total of four Red Party candidates will be elected. Since three were
elected in the single member ridings, one more will be elected on the List side. Similarly, one Blue Party candidate, two Orange Party
candidates and one Green Party candidate will be elected on the List side. The overall result is typically very similar to what is
obtained with STV or List PR – i.e., a set of MPs elected from the region that collectively closely reflects the distribution of political
preferences of the voters in that region.
SingleMemberSide
ListSide

13. Comparing Outcomes: More Representation, More Equality
Comparing the outcomes of voting using these two approaches, we see that with our current FPTP voting system,
roughly half the voters have not voted for an elected MP (with disproportionate absence of representation for voters
who do not support the largest party – shown as grey figures). The largest party ends up with a disproportionate share
of MPs. In contrast, with proportional representation, almost all voters contribute to electing an MP (in practice,
usually about 80-95% or more), and no party receives a heavily disproportionate share of the total number of seats.
FPTP Proportional

14. Comparing Outcomes: More Voters Matter
In addition, remember that voters are not all equally necessary with First Past the Post. Here, we show the surplus
voters as faded. Only the voters shown as solid figures determine which MPs got elected – barely a quarter of the
voters. In contrast, virtually all the voters would be needed under a proportional voting system (typically 80-95%).
FPTP Proportional

15. Learn More:
• Fair Voting BC - fairvotingbc.com, facebook.com/fairvotingbc
• Charter Challenge – charterchallenge.ca, facebook.com/charterchallenge
• Fair Vote Canada - fairvote.ca, facebook.com/FairVoteCanada
• PR Discussion Group - facebook.com/groups/ProportionalRepresentationCanada
• Wasted Votes - wastedvotes.ca
• UK Electoral Reform Society - electoral-reform.org.uk
• Fair Vote USA - fairvote.com
• Proportional Representation Society of Australia - prsa.org.au
• ACE Electoral Knowledge Network - aceproject.org (international)
• Institute for Democracy and Electoral Assistance - idea.int (international)