Electoral system

An electoral or voting system is a set of rules used to determine the results of an election. Electoral systems are used in politics to elect governments, while non-political elections may take place in business, <a href="/facts/Nonprofit_organization/AmXu2c85">nonprofit organizations</a> and informal organisations. These rules govern all aspects of the voting process: when elections occur, <a href="/facts/Suffrage/HFFSpSCG">who is allowed to vote</a>, <a href="/facts/Nomination_rules/H5CaMUaM">who can stand</a> as a <a href="/facts/Candidate/wapc3kU4">candidate</a>, <a href="/facts/Voting_method/jPVTljTJ">how ballots are marked and cast</a>, how the ballots are counted, how votes translate into the election outcome, limits on <a href="/facts/Campaign_finance/5JW8hvrT">campaign spending</a>, and other factors that can affect the result. Political electoral systems are defined by constitutions and electoral laws, are typically conducted by <a href="/facts/Election_commission/qITNKXfD">election commissions</a>, and can use multiple types of elections for different offices.
Some electoral systems elect a single winner to a unique position, such as prime minister, president or governor, while others elect multiple winners, such as members of parliament or boards of directors. When electing a <a href="/facts/Legislature/ycUCe91S">legislature</a>, areas may be divided into constituencies with one or more representatives or the electorate may elect representatives as a single unit. Voters may vote directly for an individual candidate or for a list of candidates put forward by a <a href="/facts/Political_party/IAKw7oEK">political party</a> or <a href="/facts/Electoral_alliance/3NSm2C29">alliance</a>. There are many variations in electoral systems.
The <a href="/facts/Mathematics/pxTouaz4">mathematical</a> and <a href="/facts/Normative_economics/3mo8HD4c">normative</a> study of voting rules falls under the branches of <a href="/facts/Economics/HYctA2Dn">economics</a> called <a href="/facts/Social_choice_theory/ztMqy1bM">social choice</a> and <a href="/facts/Mechanism_design/l3Uj6wfe">mechanism design</a>, but the question has also engendered substantial contributions from <a href="/facts/Political_science/Gqy5EoRX">political scientists</a>, <a href="/facts/Analytic_philosophy/ALSWKaQa">analytic philosophers</a>, <a href="/facts/Computer_science/lN3pEyPz">computer scientists</a>, and <a href="/facts/Mathematics/pxTouaz4">mathematicians</a>. The field has produced several major results, including <a href="/facts/Arrow%27s_impossibility_theorem/PD9oI3ky">Arrow's impossibility theorem</a> (showing that <a href="/facts/Ranked_voting/z91UKPCs">ranked voting</a> cannot eliminate the <a href="/facts/Spoiler_effect/2FTdnzPo">spoiler effect</a>) and <a href="/facts/Gibbard%27s_theorem/aAlqUNHA">Gibbard's theorem</a> (showing it is impossible to design a <a href="/facts/Strategyproofness/mQfERF7h">straightforward</a> voting system, i.e. one where it is always obvious to a <a href="/facts/Strategic_voting/5cGzDa0c">strategic voter</a> which ballot they should cast).

Electoral system open-in-new

Electoral system