Duverger's law

English

Attributed to Maurice Duverger, French sociologist who published on the subject in the 1950s and 1960s.

(political science) The principle that plurality-rule elections (such as first past the post) structured within single-member districts tend to favour a two-party system, and that the double-ballot majority system and proportional representation tend to favor multipartyism.
- 2021 January 28, Michael Tomasky, “Why a Trump Third Party Would Be a Boon for Democrats”, in The New York Times‎^[1], →ISSN:
  Out of that work emerged Duverger’s Law, which holds that single-member districts tend to produce two-party systems. […] And in the long run, the inexorable machinery of Duverger’s Law will ensure that the Patriot Party is folded back into the Republican Party.