Duverger's Law - Counterexamples

Counterexamples

While there are indeed many plurality systems with two parties, there are counterexamples:

• In the United Kingdom, the Liberal party/Alliance/Liberal Democrats have, since the February 1974 General Election, usually obtained between 15% and 25% of the vote forming a "third party" and creating a three-party system. In the 2010 election, as well as the three major parties, 8 other parties gained seats in Parliament. However, with the plurality system and constituency areas used in general elections for the UK, despite gathering around a fifth of votes consistently for over twenty years, their share of seats in parliament has not been more than a tenth in that time.

• In Canada, there are five political parties represented in Parliament. As in the United Kingdom the election system is plurality, usually resulting in a majority government of one party.

Duverger himself did not regard his principle as absolute. Instead he suggested that plurality would act to delay the emergence of a new political force and would accelerate the elimination of a weakening force — PR would have the opposite effect.

• In India, there are thirty eight political parties represented in the Parliament and like UK and Canada they have a winner-takes-all system.

These counterexamples are partly due to the effect of smaller parties that have the majority of their support concentrated in a small number of electorates rather than diluted across many electorates. William H. Riker noted that strong regional parties can distort matters, leading to more than two parties receiving seats in the national legislature, even if there are only two parties competitive in any single district. He pointed to Canada's regional politics, as well as the U.S. presidential election of 1860, as examples of often temporary regional instability that occurs from time-to-time in otherwise stable two-party systems (Riker, 1982). In the case of Canada, the highly regionalised parties are evident in province-by-province examination: while the multiparty system can be seen in the Canadian House of Commons, many of the provinces' elections are dominated by two-party systems. Quebec, for instance, is driven mainly by the sovereignist, center-(left) Parti Quebecois and the centre-right Liberal Party, while in Saskatchewan, it is the left-wing New Democratic Party and the centre-right Saskatchewan Party (a coalition of those affiliated with the Conservative and Liberal Parties). Unlike in the United States, where the two major parties are organized and unified at the federal, state and local level, Canada's federal and provincial parties generally operate as separate organizations.