The Contagion of Women Candidates in Single-Member District and Proportional Representation Electoral Systems: Canada and Norway

There is a distinct gap in women's representation in national legislatures between countries with single-member district electoral systems and those with proportional representation electoral systems. While this gap has been well documented, there have been only limited attempts at explaining its existence. After reviewing the literature on the representation gap, we turn to the party change literature and propose a modified contagion theory as one possible explanation for the gap. Contagion theory suggests that traditional parties will feel pressured to nominate more women if one of their political rivals, usually a smaller party farther to the left, starts to promote representation of women. We distinguish between macrocontagion and microcontagion and argue that especially microcontagion is more likely to occur in party list proportional representation systems than in single-member district systems. This should be true because contagion pressures are more likely to develop, and the costs of adapting to these pressures are less, in party list proportional representation systems. We formally test for microcontagion at the electoral district level in Canada and Norway, both leaders among their type of electoral systems in female representation. The data confirm our hypothesis by showing no indication of microcontagion in Canada, but evidence of such an effect in Norway.