First Past the Post electoral system: Difference between revisions

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49 C
49 C


C has the most 1st choices and wins here with 49 votes. Yet if one of A or B drops out, then the remaining candidate of the two will be a [[majority]]'s 1st choice and thus win with 51 votes. [[IRV]]/[[RCV]] guarantees such scenarios don't occur, with [[Smith-efficient]][[Condorcet methods]] giving an even stronger guarantee: if C's voters had a preference between A or B, they'd have the power to ensure their preference between the majority's candidates wins. {{fromwikipedia}}
C has the most 1st choices and wins here with 49 votes. Yet if one of A or B drops out, then the remaining candidate of the two will be a [[majority]]'s 1st choice and thus win with 51 votes. [[IRV]]/[[RCV]] guarantees such scenarios don't occur, with [[Smith-efficient]][[Condorcet methods]] giving an even stronger guarantee: if C's voters had a preference between A or B, they'd have the power to ensure their preference between the majority's candidates wins. This is also an example of FPTP failing the [[Majority loser criterion|majority loser criterion]].

{{fromwikipedia}}


[[Category:Single-winner voting methods]]
[[Category:Single-winner voting methods]]

Revision as of 07:23, 31 March 2020

Wikipedia has an article on:

A first-past-the-post (FPTP; sometimes FPP)[1] electoral system is one in which voters indicate on a ballot the candidate of their choice (their 1st choice), and the candidate who receives the most votes wins.

First-past-the-post elections only require winning candidates to receive a plurality of the total number of votes. FPTP is a common feature of electoral systems with single-member electoral divisions, and is practised in close to one third of countries. Notable examples include the United States, the United Kingdom, as well as some of the latter's former colonies and protectorates, such as Canada or India.

Fist-past-the-post is often referred to with the following terms:

  • winner-take-all
  • plurality voting
  • relative majority
  • choose-one voting
  • single-member plurality (SMP).

The term "first past the post" refers to a now seldom-used analogy with horse racing, where the winner is the first to pass a particular point (in this case a plurality of votes), upon which all other runners automatically and completely lose ("winner take all").

Activism around FPTP

Much electoral activism has centered around providing alternatives to FPTP voting.

Notes

One of the biggest complaints against FPTP is that it has a spoiler effect. This is most easily visualized by observing that FPTP passes the majority criterion but not the mutual majority criterion:

26 A>B

25 B>A

49 C

C has the most 1st choices and wins here with 49 votes. Yet if one of A or B drops out, then the remaining candidate of the two will be a majority's 1st choice and thus win with 51 votes. IRV/RCV guarantees such scenarios don't occur, with Smith-efficientCondorcet methods giving an even stronger guarantee: if C's voters had a preference between A or B, they'd have the power to ensure their preference between the majority's candidates wins. This is also an example of FPTP failing the majority loser criterion.

This page uses Creative Commons Licensed content from Wikipedia (view authors).
  1. The Department of Internal Affairs, Government of New Zealand. "More about FPP". dia.govt.nz. Retrieved 2019-02-17.