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ElectionsDuverger's Law is a principle which asserts that a first-past-the-post election system naturally leads to a two-party system. The discovery of this principle is attributed to Maurice Duverger, a French sociologist who observed the effect and recorded it in several papers published in the 1950s and 1960s. In the course of further research, other political scientists began calling the effect a “law”.
There are counterexamples: Scotland has had until recently first-past-the-post and similar systems but has seen the development of several significant competing political parties. Canada and India have multiple regional parties. Duverger himself did not regard his principle as absolute: instead he suggested that first-past-the-post would act to delay the emergence of a new political force, and would accelerate the elimination of a weakening force - proportional representation would have the opposite effect.
Additionally, William H. Riker noted that strong regional parties can distort matters, leading to more than two parties nationwide, 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).
The converse of Duverger's Law doesn't necessarily follow, as other systems may also lead to stable two-party political systems. This is particularly true in the case of countries using systems that, while they are not strictly speaking "first past the post", do not incorporate proportional representation. For instance, MaltaThis article is about the european nation. For other meanings, see this page. The Republic of Malta is an island nation in southern Europe. It consists of an archipelago in the Mediterranean Sea directly south of Italy. These strategically located islands has a single transferable voteThe Single Transferable Vote or STV is a preference voting system designed to minimise wasted votes in multi-candidate elections while ensuring that votes are explicitly for individuals rather than party lists. When promoted as a proportional representati system and what seems to be stable two-party politics. AustraliaAustralia is the sixth-largest country in the world (geographically), the only one to occupy an entire continent, and the largest in the region of Australasia. Australia includes the island of Tasmania, which is an Australian State. Its neighbouring count uses single transferable vote as well and, though not strictly a two-party system, is dominated by a major party (the Labor PartyThe Australian Labor Party or ALP is Australia's oldest political party. It is so-named because of its origins in and close links to the trade union movement. While Australians normally spell Labour with an "-our" ending, in the name of the party it is sp) and a major coalition (the LiberalThis article concerns the modern Australian political party. For the Australian Liberal party active from 1909 to 1916, see Commonwealth Liberal Party. Liberal Party of Australia Current Leader John Howard Founded 1945 Headquarters Cnr Blackall and Macqua/ NationalNational Party of Australia Current Leader John Anderson Founded 1922 Headquarters John McEwen House7 National Circuit BARTON ACT 2600 Political ideology conservative Holds government Federal (in coalition) Website The National Party of Australia is an Au coalition). Having preferential voting federally has encouraged it to spread into all the states, and to upper houses where STV gives minor parties a real chance of winning.
While some would argue that a two-party outcome is not necessarily harmful (see Two-party system), researchers and mathematicians have devoted considerable time to developing voting systemUS in 1945 Voting systems are methods ( algorithms) for groups of people to select one or more options from many, taking into account the individual preferences of the group members. Voting is often seen as the defining feature of democracy, and is best ks that do not appear to be subject to Duverger's Law.
A frequent consequence of Duverger's Law is the spoiler effect, where a third-party candidate takes votes away from one of the two leading candidates.
