“Electoral systems and party structures have important implications for how easy it is to apply gender quotas or the difficulties that advocates may encounter when lobbying for their adoption. […] [It is a commonly believed that] candidate quotas (both legislated and voluntary) are easier to implement in PR systems with large districts than in single-member districts, in which decisions on which candidate (only one candidate per party) to field in each district are much more heavily debated, and parties tend to favour male candidates due to gender-based stereotypes and powerful male incumbents. However, majority/plurality electoral systems based on single-member or multi-member districts have also been successfully combined with candidate quotas, for example in the UK, where the Labour Party has instituted a voluntary system of all-women shortlists (AWS) for selecting candidates nominated in certain districts for parliamentary elections. […] Other examples of legislated candidate quotas matched with plurality/majority systems include Senegal, which uses a parallel electoral system in which parties are required to field an equal number of male and female candidates in multi-member districts. Uganda has an additional tier of women-only districts where women are elected directly, and India has districts/wards reserved for women at the sub-national level, where women are directly elected.”[1] 

Gabrielle Bardall and Skye Christensen’s 2014 research on “Gender Quotas in Single-Member District Electoral Systems” refutes the myth of the incompatibility of quotas in single-member districts (SMD), drawing on case examples from different regional contexts, and investigates effective strategies to implement quotas in SMDs.[2] 

International IDEA published in 2007 “Designing for Equality: Best-fit, medium-fit and non-favourable combinations of electoral systems and gender quotas”, which “offers an overview of the various electoral systems and combinations with electoral quotas, by illustrating which outcomes can be expected when a certain quota is applied under a certain electoral system.”[3] The table below, extracted from this International IDEA publication, summarizes possible combinations of types of quotas for women with electoral systems.