Mixed ballot transferable vote

Method of voting using a preferential ballot

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The mixed ballot transferable vote (MBTV) refers to a type of vote linkage-based mixed-member electoral system where a group of members are elected on local (lower) tier, for example in single-member districts (SMDs). Other members are elected on a compensatory national (upper) tier from a list and voters cast a single ballot where they may indicate their preferences separately.[1]

A dual vote mixed system is not necessarily a mixed ballot system, particularly the ones using separate ballots for the two votes. This article is primarily about systems using mixed ballots. For the dual vote, hybrid versions of parallel voting and MSV used in Hungary and formerly used in Italy for national elections, see scorporo.[2]

## Overview

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Unused votes from the lower tier are counted on the upper tier in a compensatory way using a (partial, positive) vote transfer mechanism. This tied, preferential nature of the dual ballot makes it different from mixed-member proportional (seat linkage compensatory) and parallel voting (non-compensatory) systems, which also use two votes for the two tiers. How proportional the outcome is depends on among other factors, the rules (what counts as "wasted" vote) and parameters (e.g. the number of compensatory seats) used in the system.[3]

In Hungary, elections to the National Assembly use a dual vote based positive vote transfer system,[4] where votes for candidates that did not win a seat are added along with excess votes for the winner in the seat to the list votes.[5] This has plurality SMDs and also partially compensates winning candidates, however, that system uses a parallel voting component to count list votes (which are located on separate ballots).

A system formerly used in Italy, scorporo is also a dual vote and vote linkage based mixed electoral system, but differs from MBTV in that it uses negative vote transfer as its compensatory mechanism compensation. These systems lack the "transferable" (preferential) part of MBTV, in favour of an automatic vote transfer based on party affiliation.

mixed electoral systems

with compensation

| (mixed) single vote  | (mixed) dual vote

|
|

Seat linkage  | MSV (top-up) | MMP

AMS

AV+

Vote linkage  | MSV (positive vote transfer)

DMP

| Hybrids (MSV combined with parallel voting):

* Positive vote transfer: the Hungarian system
* Negative vote transfer: the Italian system (Scorporo)

MBTV

## Variations

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### Plurality

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The simplest type of MBTV system allows two single choices on the ballot: one for a local candidate, one for a party list. This type of ballot is also used in the electoral system of Germany[6] and New Zealand.

### Ranking

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A ballot can allow either the voter to rank the candidates or the party lists or both, in this case rankings can be used for a system of elimination, like that of instant-runoff voting (to determine local winners and which parties pass the entry threshold). If ranking of both is allowed, the ballot design can also allow to intermix the rankings, providing a full ranking.[1]

The ranked ballots can also be used for elections by STV on the local tier, an example is a proposal by Schulz,[7] where not only can voters rank parties intermixed with candidates on a local level, but another party vote can be cast for the MMP-type of compensation (seat linkage). The system utilizes the mixed ballot by providing that if a party has received overhang seats, then only a certain share of those ballots which have contributed to the election candidates of that party will be considered when counting the party votes. The rest of those ballots are considered to have been cast for the party of those candidates who got elected, which avoids split ticket voters double voting power.

### Other

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MBTV systems may be designed around other systems, for example approval and proportional approval voting.

## Usage of mixed ballots

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A mixed ballot used in the 2005 elections to the German Bundestag

The German electoral system, which, while it falls under the category of MMP systems due to its seat linkage mechanism, also uses a mixed ballot on which the first vote (Erststimme) and second vote (Zweitstimme) are both single choice votes. In addition, as in MBTV, not all ballots are used in the compensatory tier, such namely ballots cast for independent candidates who have won a district seat and parties below the electoral threshold.[6] This mechanism makes it similar to the preferential interpretation of the mixed ballot when it would be used in a purely vote linkage based system.

## References

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1. ^ a b https://doi.org/10.13140/RG.2.2.15129.34407 Electoral incentives and the equal value of ballots in vote transfer systems with positive winner compensation
2. ^ Political Capital (2012). "The New Electoral Law in Hungary — In-depth Analysis" (PDF).
3. ^ Golosov (2013). "The Case for Mixed Single Vote Electoral Systems". The Journal of Social, Political, and Economic Studies.
4. ^ "2011. évi CCIII. törvény az országgyűlési képviselők választásáról" [Act CCIII. of 2011. on the election of members of the National Assembly] (in Hungarian).
5. ^ Political Capital (2012). "The New Electoral Law in Hungary — In-depth Analysis" (PDF).
6. ^ a b "Federal Elections Act, as last amended by Article 2 of the Act of 3 June 2021" (PDF). 3 June 2021.
7. ^ Schulze, Markus. "The Schulze Method of Voting".

## See also

[edit]

* Mixed single vote
* Mixed-member proportional representation
* Scorporo or negative vote transfer systems
* Instant-runoff voting
* Semi-proportional representation
* List of electoral systems by country

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Electoral systems

Part of the politics and Economics series

Single-winner|

* Approval voting
* Combined approval voting
* Unified primary
* Borda count
* Bucklin voting
* Condorcet methods
* Copeland's method
* Dodgson's method
* Kemeny–Young method
* Minimax Condorcet method
* Nanson's method
* Ranked pairs
* Schulze method
* Exhaustive ballot
* First-past-the-post voting
* Instant-runoff voting
* Coombs' method
* Contingent vote
* Supplementary vote
* Simple majoritarianism
* Plurality
* Positional voting system
* Score voting
* STAR voting
* Two-round system
* Graduated majority judgment

Proportional|

| Systems|

* Dual member
* Mixed-member (Additional member)
* Mixed single vote
* Party-list
* Proportional approval voting
* Rural–urban
* Sequential proportional approval voting
* Single transferable vote
* CPO-STV
* Hare-Clark
* Schulze STV
* Spare vote
* Indirect single transferable voting

|

Allocation|

* Highest averages method
* Webster/Sainte-Laguë
* D'Hondt
* Largest remainders method

Quotas|

* Droop quota
* Hagenbach-Bischoff quota
* Hare quota
* Imperiali quota

Mixed|

* Parallel voting
* MMP
* Additional member system
* Alternative vote plus
* Mixed single vote
* Mixed ballot transferable vote
* Scorporo

Semi-proportional|

* Single non-transferable vote
* Limited voting
* Cumulative voting
* Satisfaction approval voting

Criteria|

* Condorcet winner criterion
* Condorcet loser criterion
* Consistency criterion
* Independence of clones
* Independence of irrelevant alternatives
* Independence of Smith-dominated alternatives
* Later-no-harm criterion
* Majority criterion
* Majority loser criterion
* Monotonicity criterion
* Mutual majority criterion
* Participation criterion
* Plurality criterion
* Resolvability criterion
* Reversal symmetry
* Smith criterion
* Seats-to-votes ratio

Other|

* Ballot
* Election threshold
* First-preference votes
* Liquid democracy
* Spoilt vote
* Sortition
* Unseating

Comparison|

* Comparison of voting systems
* Voting systems by country

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