Editing Parallel voting (section)

=== Compared to MMP and AMS ===
Parallel systems are often contrasted with [[Mixed-member proportional representation|mixed-member proportional systems]] (MMP) or the [[additional member system]] (AMS). There are a unique set of advantages and disadvantages that apply to these specific comparisons.

A party that can [[gerrymander]] local districts can win more than its share of seats. So parallel systems need fair criteria to draw district boundaries. (Under MMP a gerrymander can help a local candidate, but it cannot raise a major party’s share of seats, while under AMS the effects of gerrymandering are reduced by the compensation)

[[Japan]], and subsequently [[Thailand]] and [[Russia]] adopted a parallel system to provide incentives for greater party cohesiveness.<ref>{{Cite book |date=2016 |title=Mixed-Member Electoral Systems in Constitutional Context |url=http://dx.doi.org/10.1353/book.52095 |doi=10.1353/book.52095|isbn=9780472121588 }}</ref> The party is sure to elect the candidates at the top of its list, guaranteeing safe seats for the leadership. By contrast, under the MMP or AMS system a party that does well in the local seats will not need or receive any compensatory list seats, so the leadership might have to run in the local seats.

Certain types of AMS can be made ''de facto'' parallel systems by tactical voting and parties using decoy lists, which (other) MMP systems generally avoid. This specific type of tactical voting does not occur in parallel voting systems as there is no interaction between its systems to exploit in a way that makes it irrelevant. However, other types of tactical voting (such as compromising) are more relevant under parallel voting, than under AMS, and are virtually irrelevant under MMP.{{Citation needed|date=April 2022}} Tactical voting by supporters of larger parties in favour of allied smaller parties close to a threshold, to help their entry to parliament are a possibility in any parallel, AMS or MMP system with an electoral threshold.

Parallel systems support the creation of single-party majorities more often than MMP or AMS systems, this may be a positive or a negative depending on the view of the voter.