Editing Parallel voting (section)

{{short description|Mixed electoral system}}
{{Redirect|Supplementary-member system||Additional-member system|and|Mixed-member proportional representation|and|Majority bonus system}}
[[File:Parallel voting FPTP list.png|thumb|A diagram of a common mixed system using parallel voting. The local tier (here FPTP) and the list tier have no interaction.]]
{{electoral systems}}

In [[political science]], '''parallel voting''' or '''superposition''' refers to the use of two or more [[Electoral system|electoral systems]] to elect different members of a legislature. More precisely, an electoral system is a superposition if it is a mixture of at least two tiers, which do not interact with each other in any way; one part of a legislature is elected using one method, while another part is elected using a different method, with all voters participating in both. Thus, the final results can be found by calculating the results for each system separately based on the votes alone, then adding them together. A system is called fusion (not to be confused with [[Electoral fusion in the United States|electoral fusion]]) or [[Majority bonus system|majority bonus]], another independent mixture of two system but without two tiers. Superposition (parallel voting) is also not the same as "[[Coexistence (electoral systems)|coexistence]]", which when different districts in the same election use different systems. Superposition, fusion and coexistence are distinct from dependent [[Mixed electoral system|mixed electoral systems]] like [[Mixed-member proportional representation|compensatory]] (corrective) and conditional systems.  

Most often, parallel voting involves combining a [[winner-take-all system]] with [[party-list proportional representation]] (PR).<ref>{{Cite web |title=Parallel — |url=https://aceproject.org/main/english/es/ese01.htm |access-date=2022-04-21 |website=aceproject.org}}</ref> While [[first-preference plurality]] with PR is the most common pairing in parallel voting, many other combinations are possible. 

The proportion of list seats compared to total seats ranges widely; for example 30% in Taiwan, 37.5% in Japan and 68.7% in [[Armenia]].<ref>Reynolds et al (2008), ''Electoral System Design: The New International IDEA Handbook'', Sweden: International Institute for Democracy and Electoral Assistance, pg. 104</ref> Parallel voting is used in both national parliaments and local governments in [[Italy]], [[Taiwan]], [[Lithuania]], [[Russia]], [[Argentina]], and other countries, making it among the world's most popular electoral systems.{{Cn|date=August 2024}}