The debate about the advantages and disadvantages of single-member and multimember districts overlaps, to a large extent, with the debate over plurality or majority systems and proportional representation systems. This is because plurality and majority systems usually employ single-member districts, and proportional representation systems use multimember districts.
For the purpose of boundary delimitation, single-member districts
- ensure geographic representation
However, single-member districts
- must be redrawn on a regular basis to maintain populations of relatively equal size;
- are usually artificial geographic entities whose boundaries do not delineate clearly identifiable communities, and as a consequence, the entities have no particular relevance to citizens;
Multimember districts:
- can more easily reflect administrative divisions or communities of interest within the country because there is flexibility with regard to the numbers of representatives per district and, therefore, the size and geographic composition of the district; and
- need not change boundaries, even if the population of a district increases or decreases, because the number of representatives elected from the district can be altered;
Advantages of Single-Member Districts
Supporters cite several advantages, namely that single-member districts:
- provide voters with strong constituency representation because each voter has a single, easily identifiable, district representative;
- encourage constituency service by providing voters with an easily identifiable "ombudsman";
- maximise accountability because a single representative can be held responsible and can be re-elected or defeated in the next election;
- ensure geographic representation.
Disadvantages of Single-Member Districts
In citing disadvantages, critics point out that single-member districts:
- must be redrawn on a regular basis to maintain populations of relatively equal size;
- are usually artificial geographic entities whose boundaries do not delineate clearly identifiable communities, and as a consequence, the entities have no particular relevance to citizens;
- because of their tendency to over-represent the majority party and under-represent other parties, cannot produce proportional representation for political parties.
Conclusion
The strengths of single-member districts rest in the close ties between representatives and constituents, the accountability of representatives to the voters, and constituency service. Because single-member districts are used in conjunction with plurality or majority voting rules, they are also said to foster strong and stable government.
