So electoral systems matter. What are the major ways that they differ?
People who study electoral systems
usually distinguish between three characteristics. It is the different
combinations of these that shape an electoral system.
- District Magnitude (M):
Usually, we
divide up a country into a number of districts. The district magnitude
refers to the number of seats each district elects. In Canada, only one
Member of Parliament is elected from each constituency, so the district
magnitude equals one. Canada’s system is therefore referred to as a
single-member system. In the PR simulation above, we treated each province
as one electoral district. The district magnitude of Nova Scotia was 11.
Different countries vary in how they do this. Some, such as Israel, treat
their entire country as one electoral district.
- Electoral Formula:
This refers to how
it is decided which candidate wins within each riding. In Canada the
electoral formula is simple: the candidate with the most votes wins (in
other words, we give the seat to the candidate with a plurality of the
vote; Canada’s electoral system is sometimes called a single-member
plurality system). In PR systems the actual electoral formula is usually a
little more complex, but the idea is to divide up the seats in the
district between the parties according to their share of the popular vote.
A party with 35% of the vote should get 35% of the seats. Other countries
use majoritarian systems where we require the winning candidates to get
the support of a majority of the electorate.
- Ballot Structure:
This refers to how
voters express their preferences on ballots. In Canada, voters simply mark
a single X beside the candidate of their choice. Other systems, however,
might require voters to mark several Xs or numerically rank their
preferences.
|
