Many electoral systems, both plurality/majority and proportional, have a single tier of representation: each voter in the country votes once and there is one set of elected representatives. In one-tier List PR systems, the lists may be at national level, as in Namibia and the Netherlands, or at regional level, as in Finland and Switzerland.
In mixed systems, there are usually two tiers of representatives, those elected under the plurality/majority system and those elected under the proportional system. In Hungary, however, there are three tiers: plurality/majority representatives of single member districts elected using TRS; and representatives at both regional and national levels elected using List PR.
It is also possible for an electoral system to have two tiers without being mixed in character. Two-tier proportional systems may have both national and regional lists (as in South Africa) or regional lists only (as in Denmark). In the two-tier plurality/majority system of the British Virgin Islands, there are representatives elected from single-member districts using FPTP and representatives elected from the Islands as a whole using Block Vote.
Table 6: Variations on Proportional Representation

Electoral systems with two or more tiers need to be distinguished from hybrid systems, in which one part of a country elects its representatives using one electoral system, and another distinct part of the country elects representatives using a different system. In Panama, about two-thirds of the representatives are elected from multimember districts using List PR, while the remaining third are elected from single member districts using FPTP with no overlap of the two types of districts.
Table 7 summarizes advantages and disadvantages of the principal electoral systems. It is important to keep in mind that the advantages and disadvantages presented here can vary from case to case and depend on a large number of factors. For example, turnout can in fact be high under an FPTP system, and a List PR system can produce strong legislative support for a president. Also, what is seen as an advantage in one context or by one party can be viewed as something negative in another context or by another party.
Table 7: Five Electoral System Options: Advantages and Disadvantages
