The recent push for more women parliamentarians around the world via positive action measures such as gender quotas naturally begs the question of whether the increased descriptive representation of women in parliament is making a substantive difference, in terms of the types of policies passed, behavioral norms, and procedures. How does the substantive representation of women take place? One way of measuring gendered impacts in politics is to look at the participation of Members of Parliament (MPs) in formal, parliamentary debate on key policy issues. It is reasonable to assume that one (though certainly not the only) measure of a good MP is his or her ability to contribute his or her voice and thoughts to public policy debates in parliament. Furthermore, if we consider women MPs representative of women in particular as a marginalized group, making their voices heard in parliamentary debates is perhaps one of the best ways of acting for women. As Melissa Williams (1998, 138) argues, the unique voice of women is a necessary component for women’s political equality: