Decoy list

Not to be confused with Fake party.

A decoy or duplicate list is a separate party list used to avoid the compensation mechanism in some forms of mixed-member proportional representation. A party runs all their local constituency candidates on a "fake" party-list, called the decoy list, while asking voters to strategically support the party with their second (i.e. party) vote thus technically advancing for ticket splitting. This keeps seats from the winner-take-all portion of the system from being taken into account when assigning the compensatory seats. If all parties use this strategy, a theoretically proportional system will instead behave like a parallel voting system.

The decoy list strategy can be made less effective or practical (but not eliminated) by the mixed single vote rule, where parties' seats are apportioned based on vote totals for their candidates across all constituencies. The decoy list strategy can also be eliminated by either explicitly implementing parallel voting (severing compensatory linkage) or implementing certain types of vote linkage instead. Other countries have instead attempted to prohibit the strategy, using complex systems of regulations and party registries to prevent parties from exploiting the loophole, with mixed success.