Zipper system

EN Texto em inglês Ainda não há artigo no teu idioma: trecho em inglês.

The zipper system, also known as "vertical parity" or the "zebra system", is an electoral mechanism intended to enforce gender parity in countries using party-list proportional representation with closed lists. It requires that parties alternate between candidates of either gender on their candidate lists, meaning that 50% of the candidates on the list are women and 50% are men. The zipper system is applied to election laws with the goal of establishing gender parity. More modern variants on the zipper system, based on the fair share sequence, biproportional apportionment, and other rules can enforce gender quotas much more precisely, while introducing less distortion into party lists. The zipper system requires parties to create a candidate list in which the gender of the candidates alternates between women and men so that when seats are allocated, the gender of the elected members alternates for each additional seat a party wins. Vertical parity can also be combined with horizontal parity, which works towards the same goal. Horizontal parity requires that each party also fields an equal number of candidate lists with female and male candidates at the top of the list across each constituency that the party contests. However, this does not necessarily lead to parity as one gender may be placed first in constituencies where their party is unlikely to win any seats. Some countries use gender quotas on party lists in an attempt to promote gender parity, but with no rank order rule this can be purely symbolic, as women may all be placed near the bottom of the party list and be less likely to be elected. Some countries mandate the zipper system in their electoral laws.