Editing Mixed-member proportional representation (section)

==Tactical manipulation==

=== Split ticket voting ===
In other cases, a party may be so certain of winning a large number of constituency seats that it expects no extra seats in the proportional top-up (list seats). Some voters may therefore seek to achieve double representation by voting tactically for another party in the regional vote, as a vote for their preferred party in the regional vote would be wasted. This tactic is much less effective in MMP models with a relatively large share of list seats (50% in most [[States of Germany|German states]], and 40% in the [[New Zealand House of Representatives]]) and/or ones which add "[[Leveling seat|balancing seats]]", leading to fewer opportunities for overhangs and maintaining full proportionality, even when a party wins too many constituency seats.

==== Solutions ====
The problem of ticket splitting strategies can be solved either by eliminating at least one of the two mechanisms that create the opportunity for abuse: 

# Either the double vote can be abolished, returning to a [[mixed single vote]] (the original version of MMP used in Germany), in which case voters cannot split their ticket, even if it is a sincere preference. 
# Another solution is to eliminate the seat linkage mechanism and use a vote linkage one instead, in which case most likely more compensatory seats would be needed.<ref name="Golosov 2013 p." /> A negative vote transfer based system (scorporo) retains the flaw that decoy lists can be used to abuse it, but if the two votes were tied in a [[mixed ballot transferable vote]], the potential this kind of strategic manipulation would be eliminated. However, in this a case party proportionality is not likely and overall equality of votes would depend largely on the specifics of the system (the amount of compensation).
{| class="wikitable"
! colspan="3" |Compensatory mixed systems
|-
!
!single vote systems (MSV)
!dual vote systems
|-
! rowspan="4" |Seat linkage
| rowspan="4" |'''[[Mixed single vote#Proportional systems|mixed single vote, top-up versions]]'''
* '''single vote MMP (Lesotho)'''
|'''mixed-member proportional representation (MMP)'''
|-
|'''[[additional member system]] (AMS)'''
|-
|[[alternative vote plus]] (AV+)
|-
|Hybrids: e.g. parallel voting+AMS (South Korea)
|-
! rowspan="3" |Vote linkage
|[[Mixed single vote|positive vote transfer]] (PVT/MSV)

* Hungarian (local elections)
|Hybrids:

* Parallel voting+PVT (Hungary)
* [[Scorporo|negative vote transfer/scorporo]] (Italy, 1993–2005)
|-
| colspan="2" |Others systems:
|-
|[[Dual-member proportional representation|dual-member proportional]] (DMP)
|[[mixed ballot transferable vote]] (MBTV)
|}

===Splitting parties===
{{split section|talk=Talk:Bloc party#South Korea|date=March 2024|Decoy list}}
This sort of strategy for a coalition of parties to capture a larger share of list seats may be adopted formally as a strategy. By way of example, in [[2005 Albanian parliamentary election|Albania's 2005 parliamentary election]], the two main parties did not expect to win any list seats, so they encouraged voters to use their list votes for allied minor parties.{{which|date=October 2023}} This tactic distorted the working of the model to the point that the parties that won list seats were almost always different from the parties that won constituency seats. Only one constituency member was elected from parties that won list seats. The election was condemned by the [[Organization for Security and Co-operation in Europe]] which said it failed to comply with international standards because of "serious irregularities", intimidation, vote-buying and "violence committed by extremists on both sides."<ref>[http://www.tnr.com/blog/plank/109214/stuart-stevens-shady-past-clients-revealed Stuart Stevens' ... Past Clients]| Penn Bullock| 29 October 2012| tnr.com| accessed 29.10.2012</ref> Rather than increasing the number of list seats or "overhang" seats, Albania subsequently decided to change to a pure-list system.

In an abusive gambit similar to that used in Albania, major parties feeling that they are unlikely to win a large number of list seats because of their advantage at the constituency level might choose to split their party in two, with one subdivision of the party contesting the constituency seats, while the other contests the list seats—assuming this is allowed by electoral law. The two linked parties could then co-ordinate their campaign and work together within the legislature, while remaining legally separate entities. The result of this approach, if it is used by all parties, would be to transform MMP into a ''de facto'' [[Parallel voting|parallel voting mechanism]].

An example could be seen in the [[2007 Lesotho general election]]. In this case the two leading parties, the [[Lesotho Congress for Democracy]] (LCD) and the [[All Basotho Convention]] (ABC) used decoy lists, respectively named the [[National Independent Party]] and the [[Lesotho Workers' Party]] to avoid the compensatory mechanisms of MMP. As a result, the LCD and its decoy were able to take 69.1% of the seats with only 51.8% of the vote. ABC leader [[Tom Thabane]] called the vote "free, but not fair." In the [[2012 Lesotho general election|2012 election]], the voting system was adjusted to link the local and list seats to limit the decoy lists' effectiveness, resulting in an almost perfectly proportionate election result for the competing parties.<ref>See blog articles on the 2007 and 2012 elections posted by political science professor Matthew Sobery Shugard, University of California in Davis [http://fruitsandvotes.wordpress.com/category/africa/lesotho/ Fruits and Votes – Lesotho page]. Accessed 26 April 2014.</ref>

Another interesting case is that of Venezuela, which also ended up changing its system, in this case by formally adopting a parallel voting system and legitimizing party efforts to game the MMP approach. Venezuela introduced an MMP [[National Assembly of Venezuela#Electoral system|electoral system]] in 1993, but the tactic of creating a decoy party was introduced only in 2000, by the opposition governor of [[Yaracuy]]. The tactic was later adopted by pro-Chavez parties at the national level in 2005.{{Explain|date=October 2023|reason=Which parties were created and how effective was this method?}} After the decoy list tactic withstood a constitutional challenge, Venezuela eventually formally reverted to a [[parallel voting]] system, which yields a lesser degree of proportionality compared to MMP. On [[2010 Venezuelan parliamentary election|September 26, 2010]], Chavez' party, the United Socialist Party of Venezuela, took 57.4% of parliamentary seats with only 48.2% of the vote under the new system (ignoring the role of small allied parties). One can see to what extent parallel voting had nonetheless helped to redress the balance toward proportionality somewhat by noting that Chavez' party would have taken an even larger share of assembly seats under a strict single-winner approach (71 constituency seats out of 109, or 65%).{{cn|date=June 2022}}

Another example is that of the [[2001 Italian general election]], in which one of the two main coalitions (the [[House of Freedoms]]), which opposed the [[scorporo]] system (a system compensatory system similar to MMP), linked many of their constituency candidates to a decoy list ({{Lang|it|liste civetta}}) in the proportional parts, under the name {{Lang|it|Abolizione Scorporo}}. As a defensive move, the other coalition, [[The Olive Tree (Italy)|Olive Tree]], felt obliged to do the same, under the name {{Lang|it|Paese Nuovo}}. This meant that the constituency seats won by each coalition would not reduce the number of list seats available to them. In the case the House of Freedoms list faction [[Forza Italia]], the tactic was so successful that it did not have enough candidates in the proportional part to receive as many seats as it in fact won, missing out on 12 seats. Italy subsequently changed its system.

Ahead of the [[2020 South Korean legislative election]], the electoral system was changed from parallel voting to a hybrid mixed-member proportional system, with 30 seats allocated in a compensatory manner. The opposition [[Liberty Korea Party]] subsequently set up a decoy list, the [[Future Korea Party]], to win extra proportional seats.<ref>{{cite web|url=https://en.yna.co.kr/view/AEN20191224005700315|title=Main opposition to set up satellite party for more proportional representation seats|work=Yonhap News Agency |date=24 December 2019|publisher=[[Yonhap News Agency]] |last1=Soo-Yeon |first1=Kim }}</ref> The ruling [[Democratic Party (South Korea, 2015)|Democratic Party of Korea]] condemned them for exploiting the electoral law, but nonetheless set up its own decoy list, the [[Platform Party]], in response.<ref>{{cite web|url=http://www.donga.com/en/article/all/20200425/2047133/1/Election-law-should-be-revised-before-integration-with-proportional-parties|title=Election law should be revised before integration with proportional parties|work=동아일보 |date=25 April 2020|publisher=[[The Dong-a Ilbo]]}}</ref> The decoy lists were successful on election day, with Future Korea winning 12 compensatory seats and Platform winning 11. After the election, both decoy lists merged into their mother parties. The tactic was used again in the [[2024 South Korean legislative election|2024 legislative election]].

=== Electoral thresholds ===
In systems with a threshold, people who prefer a larger party may [[tactical voting|tactically vote]] for a minor party that is predicted to poll close to or slightly below the threshold. Some voters may be afraid the minor party will poll below the threshold, and that that would weaken the larger political camp to which the minor party belongs. For example, the German moderate-right [[Free Democratic Party (Germany)|Free Democratic Party]] (FDP) has often received votes from voters who preferred the larger [[Christian Democratic Union (Germany)|Christian Democratic Union]] (CDU) party, because they feared that if the FDP received less than 5% of the votes, the CDU would have no parliamentary allies and would be unable to form a government on its own. This tactical voting also ensures that fewer votes are wasted, but at the cost of giving the FDP more seats than CDU voters would ideally have preferred. This tactic is the same in any method of proportional representation with a threshold.{{cn|date=May 2023|reason=I'm writing a thesis on this and in my literature I haven't found any sources that confirm that CDU-voters vote or have voted for the FDP because they fear it might fall under the threshold. If I, after a lot of study on this subject, can't find a source that corroborates with this, I think it is safe to say that this claim needs a source!}}

Similarly, in New Zealand, some voters who preferred a large party have voted for the minor party's local candidate to ensure it qualifies for list seats on the back of winning a single electorate. This notably occurred in the right-wing inner Auckland electorate of [[Epsom (New Zealand electorate)|Epsom]] in 2008 and 2011, where the [[New Zealand National Party|National Party]] voters gave their local vote to the [[ACT New Zealand|ACT Party]]. In this case the tactic maintained some proportionality by bypassing the 5% threshold, but is largely disfavoured by the public due to it awarding smaller parties extra list seats while parties with a higher party vote percentage that do not win an electorate receive no seats; this occurred in 2008 when ACT was awarded 5 seats on the back of one electorate seat and 3.7% of the party vote, while [[New Zealand First]] with no electorate seats and 4.1% of the party vote were awarded none. In 2011, some Epsom voters voting for the left-wing Labour and Green parties tried to block the tactic by giving their local vote to the National candidate; while it was unsuccessful, it did reduce ACT's majority over National from 12,900 to 2,300. In August 2012, the initial report on a review of the MMP system by the Electoral Commission recommended abolishing the one electorate seat threshold, meaning a party winning an electorate seat but not crossing the 5% threshold (which the same report recommends lowering to 4%) is only awarded that electorate seat.<ref name="MMPproposal">{{cite web |date=13 August 2012 |title=Review of the MMP voting system: Proposals Paper |url=http://www.mmpreview.org.nz/sites/all/themes/referendum/resources/ProposalsPaper/MMP%20Proposal%20Paper.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120901022210/http://www.mmpreview.org.nz/sites/all/themes/referendum/resources/ProposalsPaper/MMP%20Proposal%20Paper.pdf |archive-date=1 September 2012 |access-date=13 August 2012 |publisher=Electoral Commission}}</ref>