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Electoral Insight – Review of Electoral Systems

Electoral Insight – June 1999

Plurality-majority Electoral Systems: A Review

Plurality-majority Electoral Systems: A Review

John C. Courtney
Department of Political Studies, University of Saskatchewan

Plurality-majority systems include first past the post (FPTP), alternative vote (AV), block vote (BV), and two-round (TR). This summary explores their implications for the allocation of seats, regionalism, and the representation of women and Aboriginal persons in Canada.

Three considerations should be borne in mind. The first two stem from the fact that every electoral system contains distinctive elements; the third is unique to Canada.

  1. Political parties find it "rational" to pursue strategic alternatives that maximize their chances of winning. Incentives contained in any method of converting votes into seats differ from one electoral system to another. In Canada, the principal incentive for any party intent on forming a government is to appeal to a wide cross-section of voters.

    Canada's major "brokerage" parties have sought to accommodate social and regional differences under FPTP. Coalitions have been built within Canadian parties, rather than between them, reflecting an incentive contained in FPTP for parties to minimize inter-regional and inter-linguistic conflicts. It cannot be assumed that the same incentives for parties to broker social cleavages would be present in other electoral systems.

  2. Voters also have strategic choices. These are influenced by the number of votes they have been allocated, the way preferences may be ordered, and the manner of distributing votes among the candidates. Different electoral systems can prompt different voting behaviour. It cannot be assumed that every voter would support the same party under one system as another.

  3. Determining the size of the Commons is a matter separate from choosing an electoral system. Under the Constitution Act, Parliament has the exclusive power to determine the number of seats to which each province or territory would be entitled. No reference to an electoral system is contained in the Constitution Act.

    According to the Representation Act (1985), the number of seats assigned to a province or territory cannot be reduced from what it had been in 1976 or during the 1984-85 Parliament, whichever is less. A 1915 constitutional amendment assured the provinces that they will never have fewer seats in the Commons than they have in the Senate. This "senatorial floor" was included in the Constitution Act (1982) as one of the sections requiring approval by Parliament and all provinces before it could be amended.

    Any move to adopt a new formula for allocating Commons seats would require amending the 1985 statute. If the guarantees of the senatorial floor were to be changed, the Senate abolished, or changes made to the number of senators to which the provinces were entitled, a constitutional amendment would be required.

    The way in which seats are distributed within the provinces is a function of the type of system used to elect MPs. Single-member constituencies serve as the base for FPTP, AV, and TR. They could continue to be established under the existing Electoral Boundaries Readjustment Act (1985) (EBRA). For elections under BV, multi-member districts would need to be created, the EBRA (1985) would have to be altered to reflect the constituency requirements of the new electoral system, and the boundaries of the new and larger districts would have to be drawn.

First Past the Post

FPTP is the most widely used electoral system in the world. In 1997, 68 out of 211 countries, comprising 45 percent of the world's population, chose their national legislatures through FPTP. Canada was one of them. FPTP is a misnomer, for there is technically no "post" for candidates to get by. Very simply, the person with the most votes wins. To win in a two-member contest, a candidate must gain a clear majority of the valid votes cast. When three or more candidates contest an election there is no certainty that the winner will gain a clear majority.

Advantages

Disadvantages

Alternative Vote

AV is a rarely used electoral system. In AV voters are required to rank their preferences numerically on the ballot paper. The person elected is the candidate gaining a majority of the votes. If no one receives a clear majority based on the first preferences, the candidate with the fewest first preferences is dropped and that candidate's second preferences are distributed among the remaining candidates on the ballot. The process continues until one candidate eventually receives a majority of the original + transferred votes.

Advantages

Disadvantages

Block Vote

BV is a variant of FPTP in multimember districts. In 1997, 13 countries used BV. Electors are given as many votes as there are seats to be filled. In most systems, the elector is entitled to vote for individual candidates regardless of their party affiliation. Electors are free to use as many or as few votes as they wish. A variation of BV, called the party block vote (PBV), permits the elector to cast only one vote for a party list of candidates in a multi-member district, with the party receiving the largest number of votes (not necessarily a majority) electing all the members from that district.

Advantages

Disadvantages

Two-Round

TR, the world's third most commonly used system, is also known as a "run-off" or "double-ballot" system. Any candidate gaining at least a clear majority of the votes on the first ballot wins. If no one receives a majority on the first round of voting, all but the leading candidates are eliminated and a second round of voting takes place. The most common form of the second ballot system requires a majority run-off on the second ballot between the top two candidates from the first round of voting. In some TR systems, all candidates receiving a certain minimum percentage of the votes on the first round are entitled to run on the second ballot. When more than two candidates compete on the second ballot, a simple plurality of the vote is all that is needed to win.

Advantages

Disadvantages


Note: The opinions expressed are those of the authors; they do not necessarily reflect those of the Chief Electoral Officer of Canada.