There are countless electoral system variations, but essentially they can be divided into 12 main systems, the majority of which fall into three broad families. The most common way to look at electoral systems is to group them according to how closely they translate national votes won into legislative seats won, that is, how proportional they are. To do this, one needs to look at both the votes-to-seats relationship and the level of wasted votes.

If we take the proportionality principle into account, along with some other considerations such as how many members are elected from each district and how many votes the voter has, we are left with the family structure illustrated in figure 1.

Figure 1 - The Electoral Systems Families

For example, South Africa used a classically proportional electoral system for its elections of 2004, and with 69.69 per cent of the popular vote the African National Congress (ANC) won 69.75 per cent of the national seats. The electoral system was highly proportional, and the number of wasted votes (i.e. those which were cast for parties which did not win seats in the Assembly) was only 0.74 per cent of the total. In direct contrast, in Mongolia in 2000, a Two-Round System only requiring a plurality of 25 per cent of the votes for candidates to be elected resulted in the Mongolian People’s Revolutionary Party (MPRP) winning 72 seats in the 76-member Parliament with around 52 per cent of the popular vote. This result was mirrored in Djibouti’s Party Block Vote election of 2003 when all 65 legislative seats were won by the Rassemblement Populaire pour le Progrès with 62.7 per cent of the vote.

However, under some circumstances, non-proportional electoral systems (such as FPTP) can give rise to relatively proportional overall results, for example, when party support is concentrated in regional fiefdoms. This was the case in another Southern African country, Malawi, in 2004. In that election, the Malawian Congress Party won 30 per cent of the seats with 25 per cent of the votes, the United Democratic Front won 27 per cent of the seats with 25 per cent of the votes, and the Alliance for Democracy won a little more than 3 per cent of the seats with just under 4 per cent of the votes.

The overall level of proportionality was high, but the clue to the fact that this was not inherently a proportional system, and so cannot be categorized as such, was that the wasted votes still amounted to almost half of all votes cast.

Equally, some design factors accentuate disproportionality. Systems with a high level of malapportionment often produce disproportional results, as do proportional systems with high thresholds—which can result in a high level of wasted votes, as in Turkey in 2002, where a 10 per cent threshold resulted in 46 per cent of votes being wasted.

Figure 2 - Electoral System Families

CC logo Reproduced by permission of International IDEA from Electoral System Design: The New International IDEA Handbook © 2005 International Institute for Democracy and Electoral Assistance The electronic version of this publication is made available under a Creative Commons Attribute-NonCommercial-ShareAlike 3.0 (CC BY-NC-SA 3.0) licence. You are free to copy, distribute and transmit the publication, and to remix and adapt it, provided it is only for non-commercial purposes, that you appropriately attribute the publication and that you distribute it under an identical license. For more information on this licence see: http://creativecommons.org/licenses/by-nc-sa/3.0 .