Duverger's law and the meaning of canadian exceptionalism

Durveger's law: plurality rule elections result in two-party competition, structured within single-member districts tend to favor two party system. In political science, Duverger's law is a principle which asserts that a plurality ruleelection system tends to favor a two-party system. This is one of two hypotheses proposed by Duverger, the second stating that “the double ballot majority system and proportional representation tend to multipartism.

Duverger suggests two reasons why single-member district plurality voting systems favor a two party system. One is the result of the "fusion" (or an alliance very like fusion) of the weak parties, and the other is the "elimination" of weak parties by the voters, by which he means that the voters gradually desert the weak parties on the grounds that they have no chance of winning.


“The simple-majority single-ballot system favours the two-party system” and also that “both the simple-majority system with second ballot and proportional representation favour multipartism”


The plurality-duality connection is normally thought to originate in a tendency for voters to abandon preferred parties that seem certain not to do well, in favor of parties they like less but that appear to have at least some chance of victory.



WHY DOES CANADA OVERPRODUCE CANDIDATES?



Canadian voters (and/or politicians) are unusually illogical or irrational. There are also candidate explanations for Canadian (riding) multipartyism that follow the Duvergerian spirit by focusing on electoral law, and I first consider one such parsimonious alternative.


VARIATIONS IN ELECTORAL LAW



Given federalism, party systems can be hybrids in which Duverger’s two laws are in competition, especially if the fates of parties at different levels are not independent or if voters tend to form attitudes about parties without distinguishing between their different branches


Regionalism, ethnic heterogeneity and issues


The mere existence of candidates from several parties could follow from (a) small, regional-issue parties being popular and (b) larger, national parties fielding full slates of candidates throughout the country, without regard to local prospects. The major parties might run candidates even where they had little chance of winning out of a belief that having representatives in every corner of the nation is a sign of seriousness, strength, a commitment to the nation, or some such thing.


Federalism

Federalism as a proxy for “social

diversity of the sort that can support separate parties.

“Federal institutions . . . may encourage party elites to maintain smaller

regional parties rather than fuse with others as Duverger expected”.

Canadian voters appear to inhabit two different, unconnected “political worlds,” so that inferring voter strategy from correlated trends in the aggregate results at the two levels is inherently mistaken.


The law applies to districts, not national aggregates. Some of Canada’s multipartyism is attributable to the effects of voters in three provinces having been subjected to multiple electoral law.

Election results in federal systems are subject not only to the usual influences—institutional and otherwise—at work in the given electoral arena but also to “contamination” from the electoral world of the other governmental level.

Duverger's law and the meaning of Canadian exceptionalism
Brian J. Gaines
University of Illinois at Urbana-Champaign
Comparative Political Studies, Vol.32 No.7, October 1999