Scholars often claim that having a proportional representation (PR) system leads to a better inclusion of women and other minorities of power in national legislatures. Typically, we refer to the larger districts found in PR systems (e.g. Lijphart 1994, Rule and Zimmerman 1994, Katz 1997). Why do we find an association between district magnitude (the size of the electoral districts) and including more women in the legislature?
At a superficial level, we know that more candidates are picked in larger districts. This increases the likelihood that one of the women among the candidates is elected. To understand this increased probability we need to make an assumption — something rarely spelled out: We need to assume that there are only a few women standing — which is quite reasonable in most contexts. We also need to assume that women are less likely to be at the top of the ballot — which is the same as assuming that men are more likely to be at the top of the ballot.
Here are three situations to illustrate this. In situation 1, men are more likely at the top than women. Stating the obvious, this means that the men are more likely to be elected. We can imagine majoritarian systems as districts where (by definition) only the candidate at the top is picked (and then only of one of the parties). In this sense, there is nothing inherently beneficial in proportional representation as a system, or the underlying larger district magnitude: the system interacts with the placement of candidates.
In situation 2, we have a larger district, thus a larger number of candidates are elected. In the graphic, this means we reach further down the list. We have the same ballots where men are more likely at the top, but by reaching further down a woman is elected.
In situation 3, we have the same district magnitude as in situation 2 (4 candidates are elected), but there is now a third party. In terms of picking women, this is equivalent to having smaller districts, because we no longer reach as far down the lists.
With these three situations, we can also understand the concept of party magnitude introduced by Matland (1993). He argued that causally speaking, party magnitude is closer to the inclusion of women in legislatures than the district magnitude. We can calculate the party magnitude by dividing the district magnitude by the number of parties in the districts. With this, Matland implicitly acknowledged situation 3 here, and made the same fundamental assumptions outlined above: Men are more likely to take the top spot of party lists than women are. The concept of party magnitude combines the two effects of (a) reaching further down the lists when the district magnitude is large, and (b) not reaching as far down the lists when many parties are competing.
Once we have understood these two mechanisms, it is clear why the effects of party magnitude are temporarily limited — assuming a general trend towards including more women in legislatures. Matland acknowledges this limitation, but does not spell out why it exists. When few women are included on the ballots, the effect of party magnitude is limited. In this case, the likelihood of electing a woman is low, irrespective of the number of parties or the district magnitude. As more women are included, we can observe a stronger association with party magnitude. This is because of the two mechanisms: (a) more women are elected where the districts are larger, and (b) more women are elected where the number of parties is smaller. However, if women are as common as candidates as men and women are equally likely to appear at the top of the ballot, the association is low. In this case, the likelihood of electing a woman approaches 50%.
PR systems might be good for women not because of an inherent advantage, but because the larger district magnitude (which is inherent in the system) combined with candidate selection and candidate placement can increase the probability of electing women into legislatures. Put differently, just like in majoritarian systems, candidate selection and candidate placement are driving the association. Beyond specifying the mechanism, this exercise also highlights that political parties and party elites play such an important role in making sure women get into electable positions.
The literature sometimes insists on closed PR lists. This is only relevant inasmuch as the parties and party elite include more women on the ballot than the population would support or — and that’s possibly quite important — with a population that does not care enough about gender to make it a priority in elections (i.e. gender is not sufficiently salient). If we imagine a society with conservative party elites and a progressive electorate (or where the party elite assumes the population to be more conservative as they are), closed PR lists would be detrimental.
Why do we care? Having a PR system in itself is a poor explanation for changes in the inclusion of women in legislatures as we observe them across the world. By focusing on the role of political parties and the political elite may be more fruitful in understanding changes. With this, we should also research why some countries have PR systems in the first place — it might be a reflection of a more inclusive culture or tradition, something which might still be reflected in present day political behaviour, but difficult to disentangle empirically.
Katz, R. 1997. ‘Representational Roles’. European Journal of Political Research 32: 211–26.
Lijphart, A. 1994. Electoral Systems and Party Systems: A Study of Twenty-Seven Democracies, 1945–1990. Oxford: Oxford University Press.
Matland, R. 1993. ‘Institutional Variables Affecting Female Representation in National Legislatures: The Case of Norway’. Journal of Politics 55: 737–55.
Ruedin, Didier. 2013. Why Aren’t They There? The Political Representation of Women, Ethnic Groups and Issue Positions in Legislatures. Colchester: ECPR Press.
Rule, W., and J. Zimmerman, eds. 1994. Electoral Systems in Comparative Perspective: Their Impact on Women and Minorities. Westport: Greenwood Press.
Didier Ruedin 